For me, it’s the refusal to demontize them that’s particularly bad. I can understand free speech absolutists (in theory anyways, in practice you’ll find that they VERY rarely actually are and will happily censor people they disagree with like LGBTQIA+ or sex work content), but that doesn’t mean you need to actively be funding them!
When I installed fdroid from their website a month or two back it was like 2 or 3 clicks. Then whenever I want to install anything from there it’s an extra click or two over what it would be from Play.
I’ve seen people click through way more complicated processes than this without even knowing they did it. Modern computing has taught people to just keep hitting whatever the approval text is (yes windows, I really do want to copy all of these god damn files. Yes, really, I still do! Yep, again, ALL of them!)