I agree on this in general. The awkward things here are that:

a) textprotos aren't really touted by the protobuf folks as a thing to use outside Google. I'm not 100% sure why this is.

b) inside Google, there's a perception that you shouldn't use textprotos for much other than hardcoding proto values inside the monorepo (where there aren't really schema-versioning concerns). I think this perception is misplaced, you just have to be aware that a given schema is used in textprotos. Which is usually an easy thing to be aware of. This is just because the schema-versioning concerns are different than with binary photos (e.g. field renames are now breaking).

c) IIRC most parsers unconditionally reject unknown fields. I think the reason for this is highlighted in the docs: you can't safely go from a textproto with an unknown field to a binary serialisation of that proto. IIRC there are some parsers that let you parse unknown fields anyway but then I think you're a bit more tied to a specific implementation than you'd like...

One strange but quite handy alternative is actually the JSON representation. You can use .proto files as a schema but then serialise the values to JSON as there's a canonical mapping. Then you get something that's human readable but with the type safety of protos. Although of course it's not really writable since... It's JSON.