He really is a fantastic starter. Aside from the Austria lap 1 incident, I think he's only lost positions on a start once this entire year?
I would be really shocked if Hamilton suddenly found his WDC form again. It's not out of the question but I think Hamilton is a solid pickup for reasons outside of "just" driving. He's extremely popular, personable, and charismatic; he can carry the Ferrari brand for a long time, and do a lot in that respect that literally no other driver can. Him being good on-track is more of a bonus. As long as he brings in consistent points and a win or two, which I'm sure he will, he'll be fulfilling his role.
Leclerc is driving out of his mind this season and provided he doesn't randomly become bad next year, he should be the clearest title contender along with Verstappen. I truly don't think there's a better driver right now than Leclerc other than Max, so he's the only driver I would ever want Ferrari to go out of their way for. Norris, Piastri, Russell would all be sidegrades at best.
The best part about the Hamilton-Leclerc pair to me is that they are both amazing tire managers which means the SF-25 can afford to have a bit more tire wear. We saw yesterday just how great at defending Leclerc is (and multiple other times this year like with Piastri in Zandvoort). He's also really good at starts... as exhibited by the video above.
If the SF-25 fixes the SF-24's qualifying issues and Leclerc (or Hamilton) can snag poles, I imagine we'll be fighting for wins often. The key part is fixing the issues without introducing more... but that's what Serra is for.