But also having been on the receiving end of losing access to content stings.
Expectations matter.
Do you normally purchase PDFs and/or physical content of material you buy on services like D&D Beyond?
So, if context on my personal habits helps:
I have a bunch of stuff in pdf form, but I don't use most of it for active gameplay. I sometimes use it so I can have the same reference in multiple locations for doing prep when I don't want to lug around books, but I don't refer to pdfs during a session.
I have bought a few things on D&D Beyond, because that's a platform I've been using in play.
Several GMs I play under use Roll20, but I have not bought anything for it myself.
Are you okay with material being updated/changed or lost while you're in the process of running a campaign? Or maybe that you won't be able to go back and access it five years from now?
I expect my pdfs to be static, but I am the one who maintains their storage. That's on me.
I recognize that I'm not maintaining the storage of D&DB stuff, and that means it might change. I went into those purchases knowing that, and I made the purchases specifically to support current play, not play that may or may not happen years from now. I'm not really worried about the longer term there. If D&D Beyond folds, I may lose that information. I'm okay with that.
I am not a player that gets upset by rules changes, to be honest. If I'm going to play, I'm going to play - a few differences here or there aren't going to ruin the game for me. I'm... just not that uptight about it.