The Proton suite of apps have 1:1 replacements for the entire Gsuite. Some things are locked behind a subscription (email is fully free), so if you’re not into that there’s NextCloud if you can/want to self-host. Tuta is also a decent Gmail replacement. As for Gapps, there isn’t really any good replacements; MicroG breaks a lot of things and sandboxed google play services is the only other alternative (which is only available on GrapheneOS afaik).