Gmail will no longer allow users to revert back to its old design
techcrunch.com
techcrunch.com
It's a good sign. Maybe unnecessary redesigns that remove functionality and lower information density are reaching a Perl 6 moment. Instead of force migration and destroying your product, the new designs have to compete with the old ones. If it's upsetting that this means that you're maintaining two websites at once, then ditch the new design entirely and just fix the old design (that made you successful.)
This sort of thing also leads to TV shows with short lifespans.
(If it's a product that can be developed by one person, programmers may be involved instead of managers, but not much is like this any more.)
[1]: https://mail.google.com/mail/u/0/h/1pq68r75kzvdr/?v%3Dlui
Whereas with old.reddit.com the initial page load might possibly be minimally slower, but end-to-end it's still noticeably faster, because everything, including the comments, loads in one go.
On an underpowered phone with mediocre JavaScript-performance it's even worse, so old.reddit.com is even more preferable (besides the fact that you're also getting around all the "are you sure you don't want to rather view this in the app" nonsense that way), even though it means having to rely on the browser's font inflation-algorithm for getting readable text instead of having a layout that's natively written to accommodate small screen sizes.