[Arainach]

justwatch.com lets you search and discover what services have what movies.

Alternatively, DIY. As streaming became more popular, optical media and hard drives became far more cheap. Over the last 10-15 years I've ended up with more than 500 movies, all of which I own legally and most of which cost me $5 or less. They get to all of my devices through Plex (I used to use Kodi, which is fine over a LAN if that's all you care about).

A significant number of them aren't available for streaming anywhere at the moment, and plenty more would require obscure services I don't feel a need to pay for. It was a gradual upfront cost, but not that extravagent compared to the cost of paying for a couple of streaming services over that time - to say nothing of the 6-10 I'd have to subscribe to to actually have access to all of it.