Why do stocks trade at the multiples that they do and why does it become a standard? what justifies these multiples?

Just a background, ive been doing this nearing 20 years now.

im well aware that there are industry standards for valuation e.g fins are reasonable between 8-15, growth are 25-30 etc etc, nothing written in stone.

i can get the sentiment if these companies use earnings to pay dividends to shareholders or buy back, which should increase share price or pay the holder for their time.

However, many companies do not do this and it comes down to hoping that the companies maintain these multiples and that the future cash continues to buy up these positions; essentially, a buyer today needs someone to buy tomorrow at a higher price, in order to have some benefit.

So what commands these multiples in price, book value, earnings etc? who sets them? how do they arrive at these multiples?

If as an As an individual I make 100k per year and I get the inflationary increase of 2-3% per year, as a modest valuation of only 5x, my value should be 115k instead of the 102/103k.