i think first it's rare to have such powers, not that it's impossible. you need to be trained, cultivated and observed certain strict precept, which is not easy. Padmasambhava, the lotus born, if you read his story, did have the ability to fly, speed running for days and sermon the weather. He was trained by a yogi specialised in spiritual powers, but not very Buddhism if you ask me.
Second it could be our time where there are too many imposters saying they are the founder of which religion etc. our level of doubt is high, so if a Buddha did appear, we will be more sceptical. Moreover, maras can also do the same. then what is the different between Buddhas and maras. hence Buddhas advocated not to use powers unless very much necessary. They have to follow their own rules.
by the way, when we are reborn in western pureland, you too will have the spiritural powers opened. actually it's our original
abilities. we already have it in all of us, but it's just hidden. see the vows:-
5 If, when I attain Buddhahood, humans and devas in my land should not remember all their previous lives, not knowing even the events which occurred during the previous hundred thousand kotis of nayutas of kalpas, may I not attain perfect Enlightenment.
6 If, when I attain Buddhahood, humans and devas in my land should not possess the divine eye of seeing even a hundred thousand kotis of nayutas of the Buddha-lands, may I not attain perfect Enlightenment.
7 If, when I attain Buddhahood, humans and devas in my land should not possess the divine ear of hearing the teachings of at least a hundred thousand kotis of nayutas of Buddhas and should not remember all of them, may I not attain perfect Enlightenment.
8 If, when I attain Buddhahood, humans and devas in my land should not possess the faculty of knowing the thoughts of others, at least those of all sentient beings living in a hundred thousand kotis of nayutas of Buddha-lands, may I not attain perfect Enlightenment.
9 If, when I attain Buddhahood, humans and devas in my land should not possess the supernatural power of travelling anywhere in one instant, even beyond a hundred thousand kotis of nayutas of Buddha-lands, may I not attain perfect Enlightenment.
anyway i recall from Lotus sutra, The Thus Come One’s Life Span:
From the time I attained Buddhahood,
The eons that have passed
Are limitless hundreds of thousands of myriads
Of kotis of asamkhyeyas in number.
I always speak the Dharma to teach and transform
Countless millions of living beings,
So they enter the Buddha Way.
And throughout these limitless eons,
In order to save living beings,
I expediently manifest Nirvana.
But in truth I do not pass into quiescence.
I remain here, always speaking the Dharma. I always stay right here,
And using the power of spiritual penetrations,
I cause inverted living beings,
Although near me, not to see me.
The multitudes see me as passing into quiescence.
They extensively make offerings to my sharira.
All cherish ardent longing for me,
And their hearts look up to me in thirst.
Living beings, then faithful and subdued,
Straightforward, with compliant minds,
Single-mindedly wish to see the Buddha,
Caring not for their very lives.
At that time I and the Sangha assembly
All appear together on Magic Vulture Mountain,
Where I say to living beings
That I am always here and never cease to be.
But using the power of expedient devices
I manifest "ceasing" and "not ceasing" to be.
For living beings in other lands,
Reverent, faithful, and aspiring,
I speak the Unsurpassed Dharma.
But you who do not hear this
Think that I have passed into quiescence.
I see living beings
Sunk in misery, and yet
I refrain from manifesting for them
In order to cause them to look up in thirst,
Then, when their minds are filled with longing,
I emerge and speak the Dharma.
With such powerful spiritual penetrations,
Throughout asamkhyeyas of eons,
I remain always on Magic Vulture Mountain
And also dwell in other places.
When beings see the eon ending
And ravaged by the great fire,
My land is peaceful and secure,
Always filled with gods and humans,
Gardens and groves, halls and pavilions,
And various precious adornments.
There are jeweled trees with many flowers and fruits
Where living beings roam in delight.
The gods play celestial drums,
Always making various kinds of music,
And mandarava flowers
Are scattered on the Buddha and the great assembly.
My Pure Land is not destroyed,
But the multitudes see it being burned entirely.
Worried, terrified, and miserable,
Such ones are everywhere.
All these beings with offenses,
Because of their evil karmic causes and conditions,
Pass through asamkhyeyas of eons,
Without hearing the name of the Triple Jewel.
All who have cultivated merit and virtue,
Who are compliant, agreeable, and honest They all see me
Here, speaking the Dharma. http://www.buddhistdoor.com/OldWeb/reso ... otus16.htm
you don't see Buddhas/bodhisattvas all around us? i may as well see them. if you can see them, then you are enlightened. you would have achieved a realisation. meaning everyone including those that are bad to you(like Devatta) around you are Buddhas. Buddha still respect Devatta, saying about his buddhahood. if you see them as Buddhas, then you are Buddha too. if you see them as bodhisattva/arahat, you are a bodhisattva/arahat respectively. every single person around you are teaching you the dharma, Really. why cannot you see them teaching? why do you hated those who are bad to you? why do you only like those that you prefered? because there is attachment, dualism and wandering thoughts. get rid of these attachment, dualism and wandering thoughts and self, then you WILL see Buddhas all around you. they do have the original spiritual powers.