Probably because most techs feel that Ryobi is a throwaway brand. Most of us refuse to work on them. Difficult to get support and parts, and if you can find help, cost to repair is more than unit is worth repairing.
Down here we get Yardman , which is an old MTD brandRyobi USA advertised their mowers are US made. Comment on that?
FWIW I scrap about 50 ryobi line trimmers a year
I have about 100 of them in the graveyard
When some one asks if I have something that they can repair with their kids I give them a truck load of them
Some even come back for more .
As for battery or electric all I replace is blades, if I can get them through my usual wholesalers
When someone brings in a ryobi or the like I used to replace fuel lines if that was all it needed. Not any more. I don't work on them at all anymore.