There are a few alternatives in mind for me. Mailbox, posteo, disroot. Disroot is the only one among these with a free email. But posteo and mailbox do have cheap tiers. Posteo doesn’t have support for custom domains last I checked.
That’s just email. I’ve already not been using proton for almost everything else. KeepassXC for passwords, Addy.io for aliases, Syncthing and offline storage across my 3 devices instead of any Drive. VPN I rarely use so free proton is enough for that. Mullvad exists on the off chance I need it for a while (it’s a constant price per month how many ever months you choose, and you can just “top up” with some amount and it will last you the appropriate number of days).
Unless you’re somehow looking for tonnes of storage, I don’t think you need cloud services. I’ve set up just my 3 devices (phone laptop PC) to sync with each other using Syncthing. And that’s plenty of space for just personal stuff (including photos). And it’s so cheap (only the cost of the devices you’re already using, and no subscriptions). It’s something I wish most people did because of how prevalent Drive has become, even though it doesn’t seem like it’s necessary for a lot of use cases. You’re situation might be different though, just a suggestion.