Browser development is incredibly difficult. The amount of work that goes into developing a browser is a lot and there are so many moving pieces and security considerations.

It’s a massive entry barrier 

 Absolutely. Maintaining the fork and applying retrofits from upstream is an incredible amount of work. 

 lmao no, but adding critical patches that are not deployed upstream for whatever reason might be.

Do you really want to spend time building something that leaves you with such a huge dependency? 

 I don't, but someone at some point will want to do this. Impervious tried and failed. Someone will attempt it again. 

 What happened to Impervious? I saw a lot, then poof, they disappeared. 

 VC money well spent..!