You can prerender helm charts into plain old manifests and apply those. How you want to handle applying them is up to you, even helm doesn't recommend or want people to run it as a service that auto applys charts anymore. Most folks check manifests into a git repo and setup automation to apply the state of the repo to their clusters--there are tons of tools to do this for you if you want.

Definitely check out kustomize, it's not a toy and it can easily handle one main manifest with specializations for each unique deployment environment. It's a very nice model of override and patching config instead of some insane monster template and yaml generation like helm.