I set up a new project on Parcel*. It was amazing at first for getting going quickly with minimal config, but became increasingly expensive to deal with. Every week or so I'd run into what I'm calling the "webpack tax" where I'd spend twice as long having to figure out how to do something as the price for not using webpack. Every tool out there has a 95% chance of having docs (or at least a blogpost or StackOverflow…
What things are you trying to do that’s not supported with parcel? I think sometimes we make super complex front end build configurations that don’t yield much benefit over something more simple.
If you're certain it covers all of your requirements out of the box, it's a great option. Otherwise...you're probably better off configuring Webpack from the start. I've never hit an issue with Webpack that can't be solved (an likely it has already been solved by someone else).