Mining requires a powerful computer otherwise a suitable mining environment will not be created. We know that Bitcoin mining requires a lot of advanced technology with powerful computing power.
This isn't very accurate, most "powerful computers" are not suitable for
BTC mining, mining needs DEDICATED chips that do NOTHING but hash sha256, which is why they are called (application-specific integrated circuit miners), in fact, you could argue that those ASIC miners are not powerful computers by any means given that you have not defined what "computing" actually is, your smartphone is likely more powerful in general computing than the most recent miner in the market.
In the early days of Bitcoin mining, you could mine Bitcoin with a computer or laptop. At that time you were occasionally rewarded by creating a block. There was not much competition in that mining. Currently miners compete to beat each other and they also work together in mining pools.
The only reason why CPUs and GPUs can no longer mine Bitcoin is due to the increase in difficulty and not the increase of miners as people, the concept of miners competing against each other has been there from the get-go, however, the term "compete against each other" is somehow misleading, because they are not, miners compete against block target/difficulty, a hash with a nonce that's lucky enough to solve a block, even when there was only a Satoshi mining
BTC he had to compete against difficulty to solve blocks if it's just competing against "others" then satoshi would have mined the 21m bitcoin's in no time.
Furthermore, if everyone stops mining today and they leave just one miner, it doesn't mean he will the blocks which were supposed to the rest of the miners, the single miner will only get the blocks that he would have gotten with nobody leaving the network, of course, since he will need a very long time to finish the epoch, the difficulty will start to slowly adjust until him alone can mine a block every 10 mins, but that will only be possible because difficulty dropped not because "competitors" left.
it is able to provide fast exact solutions in Hash computations.
fast yes, exact, nop, ASICs produce fast-random-hashes and that's all about it.
