assuming they have limited funds for new code/art/etc., I think relaxing the rules would go a long way. let users connect with their neofriends offsite. let users mention lgbtq topics (it's 2020 for god's sake nobody's gonna have an aneurysm if I say I'm queer). a stronger community usually lasts longer.
they're also definitely missing out on merch sales. it still sells pretty well on ebay; plus I know I've personally spent like...... 70-ish dollars on miscellaneous fan-made merch of neopets IP. their deal with Overpowered fell through, which makes me think they didn't really know what they were doing, but if they'd partnered with someone who actually did, it could definitely be profitable.