I remember in the 00’s when people would complain about how ridiculous a 30 PE was for tech stocks, and how no other stock was at that ridiculous price point except tech. Guess that starship has sailed.

The "official" value of a stock is it is the current best guess of the market for all future earnings until infinity discounted back to the present at some discount rate (to account for the time value of money). That price to earnings rate is 1, because it's the definition. The "E" in PE ratio, however, is for a different time period: traditionally just the trailing 12 months (or previous completed FY- for high growth companies you will sometimes see "last month's revenue multiplied by 12" or other guesses).

This calculation is why "growth" companies dominated the stock market during the 2010's: with the Zero Interest Rate Policy that most of the developed world had, the discount rate that the markets used ended up being basically zero. In which case a market player is indifferent between a dollar in 2020 and a dollar in 2040. So if a company had a 10% chance of being worth a trillion dollars in 2040, that was worth (0.1 * 1 trillion=10 billion dollars). But with a more traditional 4% discount rate then a dollar in 2040 is worth less than half of a dollar in 2020, and that means your 10% chance of being worth a trillion dollars in 2040 has less than half of the value. Even if nothing else changed about your business, just the discount rate changing halved the value of your company.

P(rice)/E(arnings) ratio of 1 would mean it pays for itself in the earnings period.

The earnings period is 1 year.

It would mean making 100% return on investment each year. Being that low is only possible if there's reason to think the business is extremely precarious and unlikely to survive.

P/E 30 means returns of 3.33%, P/E of 20 means 5%. These are sensible numbers given people have other investment opportunities.

P/E of Tesla being 400 or so means it would take 400 years of its own profits to be able to afford to privatise itself, i.e. returns of 0.25%; being that high is a gamble that future revenue/unit time will go up by a factor of about 20 to bring it into the sensible range.

The upper bound from the grandparent comment for P/E 500-1000, says the annual return is 0.1%, which is what I saw on various current accounts, not savings accounts, not special deals, current accounts.

Of course not. If the P/E was 1, every single public company would be immediately gobbled up by Private Equity firms, who would make their money back after a few years of operation and the rest would be pure profit.

I actually dont think the world will collapse by next quarter so am willing to bear the risk of doing so by having higher P/E.

At the extremes, taking the next step is speculating because you might trip and fall and hit your head.