I did this for a while, but it's just more convenient to separate concerns and have long running sessions separate from IDE's restarts and crashes. As for the Warp's business plan - can't imagine there being many teams that would want this kind of complexity handled by terminal app and not CI pipeline.
Are there _really_ enough terminal users and companies willing to shell out $$$ to make more than 1 million gross per year?
This kind of reminds me of that prettification of the node repl fad a few years ago, but when they switched to pay only people were like "hard naw"