By its very nature, Bitcoin and most other crypto transactions are public and can be traced back fairly easily. Frankly, there are many, many wallets out there already and I don't see a reason for Proton to get in on that and dilute resources.
HOWEVER, Proton could make its Wallet truly outstanding by adding a mixer feature, similar to Tornado or Ergo. I realize this could potentially open legal implications but Proton crew is clever and can probably figure out a way around this.
Otherwise I don't really understand why Wallet even exists. It does nothing most other crypto wallets already do.