Investment has to have a thesis. If there's a strong thesis, it doesn't matter what the asset is.
Purchasing something like Pokemon Cards or DOGE back in the day would absolutely be called gambling yet people buying them had a thesis (of course not all of them) and it played out well.
That's perfect example, you're right about thesis or research and TCGs are now very on the trend but I'm scared of the hype that it's doing right now, one piece, NBA, etc. Whilst for the doge, it's unfortunate that I didn't took the gamble which was on my head way back then. So for the love of passion who did it in the past just took the gamble out of their pockets and it's now worth it.
investing in memecoins to me is also a form of gambling because gambling is typically when you invest or better said stake your money in an uncertain situation where your profit is higher based on luck. Investment is when you put your money in a position where it grows, being it slowly it fast but the potential of you winning is higher than losing and that’s why it is called investing whereas in gambling the potential of you winning and losing are the same and your chances of losing seems to be even more than your chances of you winning in a perpetual manner. Memecoins most of the times are not like that, when you invest in memecoins you are never guaranteed
IIRC, there was this meme craze on 2021 and investors rushed into it. To be specific, it was in the solana network where too many memecoins came out and with the community response to it was there's a bunch of them that profited with it. Well, that's truly a gamble, it's profitable for them and considered as an investment until it's not.