PETG has poor mechanical properties. It's largest problem is with impact resistance. If you bend or feel a PETG part, it appears ductile and you would think impact resistant. However, under sharp impact, PETG shatters and has very poor impact resistance.
PETG does have better temperature resistance then PLA+, but it's not enough to make it usable. I would use ABS over PETG for mechanical parts. For non mechanical parts, it can be great. Just not the right thing for high stress parts.