The first few series of the "new" TG format with Clarkson Hammond and May were funny. Then they just became cliches of themselves and it became really dull. Oh look, they blew a caravan up, oh no something caught fire, they hilariously tamper with each other's cars while they sleep, they crash into each other ("Hammond you blithering idiot!"), let's modify our cars in to something ridiculous - oh no it fell apart/sank/caught fire. Yawn. By the time the BBC ended it it is was tired and very boring unless you were an 11 year old child.
Then they did The Grand Tour which was more of the same. The last two seasons of GT were just awful, mostly redoing things they had done before (blowing up caravans, tampering with each others cars hilariously, overly scripted rubbish, crashing into each other, "Hammond you blithering idiot").
Top Gear also went through some bad times with Evans, LeBlanc etc because they were trying to copy the same matey format doing stupid challenges, stupid gimmicks and lame scripted gags and it was too forced.
However the last two series found their feet as they stopped trying to copy and instead found their own format, concentrating more on cars which is infinitely more entertaining than stupid forced and scripted road trips. I found the last two series far more enjoyable than the GT. Flintoff was likeable, Matt Harris was the proper car guy, and the other one was OK too. It'll be a shame if it ends, but they should just focus on cars, not stunts.