Not trusting auto repair shops

I wrote this on another sub and figured I would give this one a try too to get people's opinions.

I have a 2016 Dodge Journey that I brought in to a local shop to get the brakes looked at and the rotars if they needed it. They then recommended a few other things ( replacing leaking oil filter housing, replacing leaking struts) Thing is there's no sign of the oil level going down, no leaks on the ground, and the struts were replaced about 5000 miles ago.

It's very puzzling because less than a year ago I brought the vehicle into a dealership for some work and they gave me list of recommendations that totaled $8000, I got a second opinion from another shop and some things were on the second quote too but a lot of things listed on the first quote were not on the second one and the second one came out to only about $4,300 worth of repairs. So it makes me question weither these recommendations that shops give are essential or not, how do you generally go about knowing what you should take their word for and what you should just ignore?