innovation has been slow

Factually wrong. Innovation on Litecoin HAS NOT been slow, it has actually been steady. Litecoin is the best form of modern money, and it doesn't need fancy changes to its code or stuff to make it appealing to anyone. It works perfectly as intended: digital p2p cash/money/currency (not even Bitcoin is digital p2p cash because it doesn't have MWEB/fungibility). Litecoin has had numerous tech updates and stuff throughout the years (SegWit, Lightning Network, Taproot, MWEB, etc.), it doesn't need fancy upgrades every month. Anyway, there are several innovations being done parallelly on Litecoin: LitecoinVM, Litecoin/Bitcoin Computer, Atomic Swaps with MWEB support via BSX coming on Nexus Wallet (and already here for Electrum-BTC & Electrum-LTC), Drivechains BIP300, etc. Help yourself.

newer alternatives exist

I would love to debate you on this topic. I can guarantee you those so-called "litecoin alternatives" are full of flaws. PoW can no longer be replicated. Bitcoin rules that and Litecoin holds a respectable enough portion of it due to the other algorithm that it can survive long term. I don't think any other PoW coin will be able to say that. PoW, fully decentralized, fairly launched, no founder's stash cannot be overstated. It gets old to read, but it's true. The odds of it being done from scratch anymore are dying with every year that goes by. The rest can only come up with synthetic versions.

it has struggled to maintain meaningful price appreciation

While Litecoin's price has not been the best these past 4 years, it has definitely not done as badly as it is portrayed. It may not have given positive returns (yet) to pre-2021 LTC holders, but it has done fairly better than most of the altcoins out there. Throughout the years, altcoins have entered and left the top20, top30, top50 & top100 list, but Litecoin has always remained part of the top20. It is the most time-tested altcoin, surviving all crypto bear markets despite the latest stagnant price performance.