Products was built more around services than actual physical inventory, at least from my perspective. It's usable for standardised pricing as it pulls nicely into quotes and invoices, but it lacks many of the features you'd expect for inventory management.
I really agree with many of the posts here that an inventory solution would be great. I'm just unsure if we'd integrate this with products, assets, or have it separate entirely?
I'm in a different type of MSP role, and have ended up quite hands on with re/building a fair amount of user hardware. In the example of pulling parts out of computers (something we do as well to repair site laptops) it's really handy to know what you have in stock vs what specific components make up/are required to repair an asset. Working primarily with Dells Self Dispatch, we basically keep stock of the most common parts we need for fixes and then reorder manually to replenish stock. If I'm honest, I never actually know how many laptops / phones / accessories / components we have in stock without checking manually constantly.
I imagine we'd end up with an inventory system that integrates with products, assets and quotes/invoicing that allows for part numbers, serial numbers, barcodes, stock count & notifications, raw and markup cost, etc.
We can probably learn an awful lot from SnipeIT for general asset management (specifically statues and history), though from my previous experience it's not great either for part management and doesn't really allow for billing.