Scotty doesn't comment much on UK cars since he rarely comes across them. They don't make Avensis anymore so you're looking at an least 7 year old car.  Do they even sell the Corolla/Camry in the UK? In general Toyota makes excellent cars, but the Avensis came with a variety of engines. The 2ZR wasn't great...

2ZR engine problems are the same as for the 3ZR engine series. Among them are progressive oil consumption, unreliable cooling pump, Valvematic issues, and noisy operation

https://www.motorreviewer.com/engine.php?engine_id=155

 

In general engines for Europe don't last as long as these for America. I personally would not touch anything Valvematic, then 1.6 1WW and 2.0 2WW diesel engines, which are actually BMW N47 engines, known for timing chain problems. Some diesel engines have also oil burning problems.

You can also ask on https://www.toyotaownersclub.com/

Here we have some topics about this model

https://carkiller.com/scottykilmer/qa/avensis-2014-2-0-not-diesel/

https://carkiller.com/scottykilmer/postid/70819

https://carkiller.com/scottykilmer/qa/engine-avensis-valvematic-vs-vvt-i/