People keep bringing this up and I feel like there's a fundamental misunderstanding going on. The internet of 2010 is not the internet of today, not even close.
The average reddit user of today isn't going to stop using reddit due to problems like this because they just don't care, at all. They don't care about the new web design being a massive downgrade over the old one because they're used to every website looking like that, they have no complaints, many of them probably don't even know the old design still exists. They don't care that the app sucks and is full of ads because, again, most official apps for most websites are like that, it's the new normal. They just want to scroll through funny meme videos on their phone for a while and don't think about it beyond that, the age of the average user having standards is long, long gone.