I get this frustration. We are of an age (maybe a factor too?), diagnosed at a similar time and both stuck at a point that is not where we desire to be. Not awful but not anywhere near as good as others manage with apparently less effort. Both weight and bgl wise. (I’m also refreshing the online results tab hourly waiting on my hb1ac as I type). I posted similar frustration a couple of weeks ago.
As
@LittleGreyCat says it depends on how you define success and failure. You (we) see the goal as remission/normal bgl. He sees it as not needing to progress to additional medications and to maintain the status quo.
If I asked you would you rather stay where you are or progress and deteriorate which would you choose? That is the point. To not get worse. It might not be the ideal option but it is the better of the two. So keto is achieving a better outcome that not doing it. Eating carbs again would undoubtedly get you a worse outcome.
You are comparing last years results on a less strict regime with this years on keto. IF you are indeed LADA then deterioration is inevitable without the right treatment. To have held it so static is a massive achievement, albeit not a long term option.
Get the tests and reevaluate with the additional evidence it gives.