Reliability of all the Japanese makes of home organs, and then keyboards, has been legendary since Yamaha made their first home organ in 1959, and Kawai in 1961. Panasonic/Technics were the third of the 'big three', but there were other players in the market like JVC. I used to unbox brand new models on stage years ago - you had to be confident in them to do that!
I've used Yamaha keyboards for teaching and performance since 2000. Many have come and gone, currently I have a PSR-E443 (going to a grandchild at some point), a PSR-S970 and a Genos 1. Not one has ever given a moment's trouble, and the teaching ones had a hard life! And I've had many students with older models, some still have them!
The only things I've physically worn out have been pedals, an FC-5 and and FC-7 and only then after some years of tough use.