I commend you for your efforts and I'm sure they were appreciated even by those who switched to English with you. It sounds like you were in the infamous long awkward intermediate stage of language learning. Depending on the cadence of your language classes, three years may not be a long time. Intensive language programs with daily lessons and drills are exponentially more effective than typical language-learning programs spread out across short sessions sprinkled throughout the week/month. In my opinion, it makes a lot more sense to place newcomers in intensive learning programs on arrival than to accept they will not be functional outside of ethnic enclaves, and wait decades for their children and grandchildren to finally integrate, as other commenters suggest. It's not an easy process and we can't expect everyone to have the intrinsic motivation to do it all on their own, which is why incentives are needed.