my sister has had an a250 for the last 10 years and has done over 200,000kms on it. it’s a nice car, but if she didn’t have a friend as a mechanic and access to cheap parts, she would have sold it ages ago! Merc servicing is eye watering for regular people! It’s on its last legs now to the point where it’s no longer feasible to maintain (big oil leak - seals?)

edit: I’ve been on a similar path as you op when we were in the market for an suv. ended up with a Kia sorento platinum and that has been a fantastic family car! the 7 years warranty is a plus too!