For the last few months my monthly contribution gets swallowed up by the losses and the balance hasn’t moved lol
The broad index will, most likely, be positively skewed and still be around in 20 years. DCA makes a lot of sense.
The single stock may just go bankrupt, or become smaller and never recover (think Kodak or Nokia). DCA does not make as much sense.
And the best legal way to do that is to be a customer or prospective customer and observe that there are no other ways to accomplish what you want to.
There're a number of beaten-down tech companies that IMHO would pass that test: NET and COIN are two of them, ZOOM, probably SHOP as well (the small businesses I know on them swear by them). I'd stay away from Affirm, Peloton, Netflix and Roblox, though - those are the ones where, as a customer, I just don't get much value out of them and could easily go elsewhere.