@crinrict , in my existing pre-patch, pre-install CL save this is happening in in my game, too. I don't think skill level affects this. I've about decided that positioning of the object on the lot might. On a small lot with the workbench set up right outside the back door, the obsession is constant. I also have one on the Villareal lot in WB that is placed much farther away from the house. Although autonomous use there is quite frequent, it isn't as bad as the house where it is outside the back door. My sims aren't neglecting their needs, either.
If you want to see the obsessive behavior in progress, try downloading Highlander Crest 1 house by Buttonsginger. I use it on the empty 30X20 lot in WC. Even when NPC sims are over visiting, they are obsessed with the workbench as well. One instance was quite humorous. A household of 4 on that lot had 4 visitors over and it suddenly started to look like a contest for workbench control, lol.
After that workbench free-for-all, I found 4 incomplete projects in the household inventory. Probably because I would have a household member interact with whichever NPC was using the bench breaking off usage, only to have another sim fairly quickly exit the house and start a project. Also, the sim father had autonomouly started yet another project and I directed him to go to bed. I tried to have his son scrap the project after watering the garden. The son gave the swiping motion to it to scrap it but it didn't disappear from the workbench. I had to get the father back up to successfully scrap the project so there may be a secondary issue other than just the appeal. I haven't tried to replicate that yet.
I now put the workbenches in the household inventory and pull them out when I want to direct a sim to use one. The workbench just seems to be broadcasting a really strong appeal, especially when placed really close to a house. I don't mind autonomous use of objects like the workbench by sims at all. I've even hoped to see more autonomous usage of fun objects like the foosball table and dart board by NPCs. I don't want to see usage stopped, just toned down a wee bit for balance, if possible.
I haven't placed a workbench in an apartment. In my new save I'm in the smaller less expensive units so there isn't really any room for one. However, based on the old save's happenings, I don't think I'll be putting one into an apartment setting, lol. Sims can just go to the new Arts Center 🙂
Edited to Add: Unmodded, vanilla game.