LOL! I understand your point of view, however my customers are residential and the expense of parts and labor to install an SSD is difficult for a lot of them.
Harry Z
It's cheaper than the expense of them blaming you for their hard drive failing after you do any sort of maintenance on it. Even if you successfully clean it up you get what maybe another 5%-10% performance which becomes negligible after using the computer for a week? I'm just straight up with them, and tell them that they'll feel like it was a waste of money.
I tell people I can charge you an hour for a clean up and whatever performance boost you get out of it will probably be un-noticeable after a couple of days, OR, I can install a SSD, mirror it over, and you get your computer back better, faster, and more reliable than when you first bought it, giving you at least a 50% boost in speed. On top of that any other work like updates I need to do to it aren't a complete time sink baby sitting a terrible system.
Most go for that, its easy enough for me to image a Samsung SSD with their software and install it. With 500GB SSD's below a $100 price point I can usually make the sale at about $280 for basically 15 minutes of hands on work. It usually takes longer to communicate with the customer for dropoff/pickup, wipe it down, and collect payment than it does to actually work on it.
Maybe you need to push yourself, maybe you are mentally blocking yourself from making the sale because you don't THINK you can sell it. Give it a shot you might be surprised. If you still can't make those sales then you're either not good at selling, you're in an extremely low income area, or you just need better clients.
It's getting more and more rare these days to even see a spinner, and if I see one it goes straight into an SSD upgrade or a new computer. I am not wasting my time cleaning up a computer with a 4 year old spinner in 1.) Because it takes forever to do ANYTHING on that computer and 2.) Because I don't want the computer back several weeks later after I rip files out of it during the cleanup process pushing it into failure.
I've even shown up at clients offices with SSD's in hand, start mirroring, then goto lunch and come back after they are done then just swap them and charge them a flat rate for the whole thing.
I had a lady call me today, referred from another client. Her 10 year old computer was boot looping after a failed W10 upgrade. After explaining to her that upgrading that system in the first place is a mistake, there is a high likelihood that her hard drive is failing. I told her no matter what she needed a new computer. I walked her through booting up into safe mode, then rebooting and after some time it actually booted up. I charged her for 1/2 hour labor and she called me back asking me to do a hard drive diag on it after it finally booted.
I just straight told her I wasn't going to touch it anymore, and even if I did and the hard drive wasn't throwing errors I'd tell her she needed a new computer. If it was failing, then she needed a new computer. The end result would be the same either way and it would be pointless. She wasn't local by the way, so she probably wont be a returning client, not to mention the pandemic.
Theres more to the above story like a desktop recommendation and a recommendation to find a local tech to transfer that data since at the time it wasn't booting but people are people and she'll probably push that thing until it completely fails and she loses all her data.
I told her to call me when she buys the one I recommended to her, i5, 12gb ram, 500gb nvme and I can login to it and help her set it up remotely but either way she'll need to find someone local to transfer the data.