I had a Ryobi 18v drill from 2004 until I grew tired of the batteries taking a dive in 2012, this was me using it professionally. Granted it was not on a daily basis but it was asking more of it than your regular homeowner. My boss was cheap then what can I say. Not once though did I have to worry about any brushes or other maintenance items. I did however have a Dewalt that only lasted about 2-3 years of use before it bit the dust. The Ryobi replaced the Dewalt. I replaced my Ryobi in 2012 with a Milwaukee 18v, it served me well until it decided to part ways with me Via storm sewer 3 weeks ago. I had actually let some of the smoke out of that one but it wouldn’t die either. It just decided to jump out of my van into an awaiting storm sewer.
I think the Ryobi’s do tend to catch shit, but you know what, they work. Not a lick of problems out of it. This was as of 2012 for my experience. The speaks volumes of how long they last with us at the space. I’d like to see a cordless-athon between the different manufacturers. DMS would be probably the best place for such a test bed.
For your entertainment a picture of my Milwaukee letting out some smoke.