You are quite correct. The riders you mentioned have not gone on to be GP standard, but I would suggest all three ride in the hardest league in the world. Bar Bewley and Lambert, no other British rider is competing at that level. Of course you could say, " put them on a uk track and they would be pants" but the facts are they all ride in the main body of the team and don't if they are struggling get to drop back down to reserve. If they don’t perform they are then shipped off to the lower leagues. Out of interest, the Polish U24 league has a list of the top 100 riders. Young Aussie Keynan Rew is top. You have to go down to 35 Rowe, 38 Flint and 55 Giilkes https://ekstraliga.pl/en/se/classification-list/u24e/2024
So the above British riders should surely be a lot higher up that list, due to riding in our top league?