Transmission fluid

Hi friends! This seems to be a common misconception, so I’d love some advice as I don’t really know what to do here. I have a Subaru forester, around 105k miles. Apparently, the transmission fluid has not been changed since around 33k miles before I even got the car. I’m on top of oil changes and I usually just take it to my subaru dealership as I don’t know much about cars. Last week, I took it in to a local mechanic because I needed some parts and I knew it would be cheaper. They called me and said my transmission fluid is black and chunky (picture the mechanic sent me attached) and it looks like it has never been serviced, and they’re recommending I replace the entire transmission. So I talked to subaru, where they said it is a “lifetime” fluid and they do not routinely check that when servicing a vehicle. My question is, if the car is still running, why would I need to replace the entire transmission? Can’t I just replace the fluid? Why does Subaru not check for this if it’s not actually “lifetime”??? I’m just frustrated because I thought I was doing everything right by my car and now I feel like I’m at a loss because I don’t know if I can afford an entirely new transmission. Any advice would be appreciated:)

Hi friends! This seems to be a common misconception, so I’d love some advice as I don’t really know what to do here. I have a Subaru forester, around 105k miles. Apparently, the transmission fluid has not been changed since around 33k miles before I even got the car. I’m on top of oil changes and I usually just take it to my subaru dealership as I don’t know much about cars. Last week, I took it in to a local mechanic because I needed some parts and I knew it would be cheaper. They called me and said my transmission fluid is black and chunky (picture the mechanic sent me attached) and it looks like it has never been serviced, and they’re recommending I replace the entire transmission. So I talked to subaru, where they said it is a “lifetime” fluid and they do not routinely check that when servicing a vehicle. My question is, if the car is still running, why would I need to replace the entire transmission? Can’t I just replace the fluid? Why does Subaru not check for this if it’s not actually “lifetime”??? I’m just frustrated because I thought I was doing everything right by my car and now I feel like I’m at a loss because I don’t know if I can afford an entirely new transmission. Any advice would be appreciated:)