That doesn't feel like the right word: it's mandatory but you're still talking about a very competitive browser engine and the security rationale for blocking third-party JIT is not without merit even if I wish they'd relax it[1]. This feels similar to the IE 5-6 era: it got really bad by the end after Microsoft removed most of the team but there was an earlier period where they were forcing it on users but most developers would have acknowledged it having good performance and features relative to the competition.
In this case, it's especially complicated by the fact that iOS is the primary check on web standards meaning whatever Google chooses to implement. Mozilla isn't without influence but there's no incremental way to chip away at Apple's market-share the way they have with Google/Youtube.com pushing Chrome at Firefox users short of making Android phones far more competitive.
1. Say by requiring strong commitments to code quality and response time, which would allow e.g. Firefox and Chrome but not Adobe-level security commitments.
In this case, it's especially complicated by the fact that iOS is the primary check on web standards meaning whatever Google chooses to implement. Mozilla isn't without influence but there's no incremental way to chip away at Apple's market-share the way they have with Google/Youtube.com pushing Chrome at Firefox users short of making Android phones far more competitive.
1. Say by requiring strong commitments to code quality and response time, which would allow e.g. Firefox and Chrome but not Adobe-level security commitments.