If you are riding at high speeds, doing MTB, or some other sporty activity, on a carbon fiber bike with pro components, then sure. If you’re just commuting or going to the shops or whatever, on a cheap old bike, then you can probably just fix everything yourself and be fine. I’ve been doing almost all servicing on my bike myself, screwed up plenty of stuff (including my rear brakes once), and it was fine. I just stopped using the front brakes and learned a lesson.
If you are riding at high speeds, doing MTB, or some other sporty activity, on a carbon fiber bike with pro components, then sure. If you’re just commuting or going to the shops or whatever, on a cheap old bike, then you can probably just fix everything yourself and be fine. I’ve been doing almost all servicing on my bike myself, screwed up plenty of stuff (including my rear brakes once), and it was fine. I just stopped using the front brakes and learned a lesson.
My worst injuries ob my bike have been at low speed. “Insignificant” things can cause bad accidents; especially if you’re riding around cars.