First, what “need” does the F-35 fulfill? So far as I can see, it is a platform designed to fulfill political needs first, tactical combat operations second.
Why was or is there a need to create a joint-role platform with other countries? Their command and control infrastructure cannot keep up with ours, so I see no reason under the sun to hamper or distort *our* requirements to deal with those of our “allies.” I put that word in quotes, because if a real shooting war ever breaks out, we’ll find out just what we’ve found out in Iraq and Afghanistan - they’re ‘allies’ in the sense that they’ll hold our coats and offer ‘constructive advice’ from the sidelines.
Second, we’ve learned the hard way with the F-111 that multi-role aircraft usually either suck, or they become exorbitantly expensive.
In that light, why would we want to replace the F-35 with anything like it? Let’s drop the mental masturbation of allowing our “allies” to set any specifications on OUR fighter aircraft and build what WE need.
What specifications did the allies set on the JSF so as to affect its likely performance? The JSF was and remains primarily a US programme with industrial participation for allies.
The F-111 was not meant to be a multi-role aircraft-it was adapted later to a naval role at which it sucked. But it did more than a decent job in the strike and electronic warfare roles.