I disagree on your assessment of the French teams compared to the English ones. I think there are at least a few more French teams who would not have a problem avoiding relegation in the prem and beating sides like Crystal Palace, West Brom, Swansea, Stoke and West Ham on regular basis and enough others that would by no means struggle in the Championship. Sure the bottom of the French table is pretty bad compared to the biggest teams in the world, but so are most teams playing in the Championship.

I think it's pretty clear that tLigue 1 is still a great place for a young player to play and it's still a significantly better destination than the Championship for a young player who wants to develop and to be noticed. Look at the outgoing talent coming from both leagues and you'll see a significant difference.

I wholeheartedly agree with your second point about Ajax and Benfica. The fact that some leagues are turning into feeder leagues for the wealthier ones is making international club football a bit more boring with fewer and fewer clubs coming from outside the top 5 leagues that capable of any upsets as all their talent gets mopped up by the big boys. But this is what makes those leagues perfect for younger players right now and this is what British and especially English young players are missing out on. Ajax is a much better destination for a young footballer than any club in the Championship even if you think the Championship is a better league than the Eredivisie. Manchester United are much more likely to sign a player from Ajax rather than the Championship, right? Average top-tier football is still a better carrier choice and a better experience than high-level second-tier football not just because of the competition, but because of the stadiums, fans and staff and that's also important.

On top of this, I'm not sure the style of play in the Championship is the best environment for expanding an English footballer's skill set.