There are couple details missing in your question, which is a decent question that many folks also asked before you.

First, there are many self-custodial lightning wallets where you hold your keys, like Blixt, Breez, Phoenix, OBW, or Muun.

Second the rate of "topping up" (or withdrawing) will balance itself based on current onchain fees. Third, we are still in the beginning and there are many possibile next steps in scaling. (Note that scaling is a never ending game, it's just about getting to the next step), some examples are fedimint, opening many channels in a single transaction, channel factories, PTLV saving on bytes, etc.

Don't be confused by WalletOfSatoshi, which is indeed custodial and you don't hold your own keys. There are other wallets...