So, you are basically trying to forecast how much it may cost to own a car, i.e. compute math expectation of owning expenses... I think you may be slightly off the track when you start from a list of possible repairs for a generic car.

Better start with a list of possible cars that suit you needs. From a maintenance point of view there's a general rule that the more expensive a car was originally, the more you'll need to repair it now (even if it cost you little to buy), because of parts&labour cost. Fixing the same issue on an old and on a new car costs the same. So overall, in general "premium" segment cars cost way more to maintain than "economy" cars. Second important hint: you are interested in car models that are easy to maintain/repair in your local area. For example, if you want 2015 Mazda cx-5, but there are no decent mechanics in your region who know exactly this model, or there are some but they have shady reviews, you are going to have quite bad experience with that car even if these cars in general are extremely reliable.

After you've made a list of suitable cars, for each car find a community of people who use them. There are billions of online forums, facebook groups, whatsapp chats and etc&etc of car enthusiasts who already use the same car model you are interested in. Observe their chats, ask them directly about most likely issues one would encounter with the model you like. On that stage you'll be able to compile a real list of possible issues along with some probability estimates (i.e. how likely it's to encounter a particular issue).

Having such list of issues and the likelihood of each issue occurrence for each car model, now you'll be able to estimate the costs of repairs - tied directly to the car model you need, not some abstract car.

The final number will be a math expectation = <cost_of_repair>*<probability_of_the_issue>. If you going to have an issue A that costs $2000 to fix, each year with a probability 25%, then on average you need to allocate $500 annually to handle the issue. Compute and sum over all issues and you are done for the model.

So, once you do it for every car model in your list, you'll have some (rough) estimates of maintenance costs for them to make a better decision.

PS: regarding "It's actually way worse than I thought" - my offroader is a 2008 remake of some other older car and basically it's very decent exemplar of 199x technologies slightly sprayed by a little bit of modern 200x electronics. I love it because of it's reliableness and being relatively easy to fix (every summer I do 6000+km trip to a very remote and wild place that extremely demanding to a car and puts a lot of stress on it because of very bad "roads", deep water-filled obstacles & so on, - the car haven't failed me yet) and I'm scared of a hell of a moment when I'll be forced to abandon that car. Because there were a lot of decent reliable new offroaders 15 years ago that were able to handle tought conditions well and there are basically just none today. I'm not a madman to drive an electronic filled "mall crawler" to a place where a nearest living human may be in 50+km away over a brown bear infested forest... I just have nothing to choose from if I'm to change the car...