My ideas:
1.
It is senseless as an "investment" in plenty of companies, specifically if their stocks do not offer dividends nor provide any voting power, as then your "gains" will come actually from other new "investors" buying also those "stocks" for a higher price, not from a company actual production.
See this video:
2.
Most of the richest people of the world are so rich because they made some real business, with real factories, offices, and, very specially, workers. They did not buy the stocks at the exchange, but they started the business from 0 or bought it in private deals, and then developed it further.
If you want to be rich, you have to do this, not just buying tiny fractions of companies already developed and reselling them, that is something completely different.
3.
I would buy then businesses that actually give dividends and voting power, why? Not necessarily because of the dividends themselves, but because you will know then that the value is not coming from pure senseless speculation about a useless property title, a la NFT. The value of those stocks is actually being affected by whatever the company make.
I would buy companies from all over the world, and from sectors that you think will be thriving in the coming future. I would take advantage of the ETF's, instead of buying specific companies.
And, finally, the most important thing, I would not expect this to make me become rich. To have such dream is as senseless as hoping to become a millionaire trading domain names.