If you want to build a toaster not so much. You could just slap a CE sign on and probably get away with selling it via online platforms. That however means you guarantee for the compliance.
You also need a manual in the language of the nation where you want to sell it and a model/serial number and a risk analysis. That is not nothing, but the motivated individual could learn all of that in a few years, if they are somewhat intelligent.
Sure depending on what area you are operating in the catch might be even knowing what all those norms are and the fact that we sometimes have to pay to even read the norms is a friggin crime. But it is probably a good thing that there are some requirements one needs to fulfill to e.g. becoming a commercial airplane manufacturer.
Regulatory capture (big corps demanding stricter regulation to root out their smaller competition) is a thing. But not with the toaster industry.
There might be regulation that is too much, also in the field of electrical engineering (and I am a certified EE), but most of it (especially regarding toasters) is pretty useful if you want to sleep sound.
This is not about making a toaster. I could make one using a long piece of wire and a transformer. It is about making a toaster that has a certain standard and does not kill people, burn down houses and/or interferes with radio traffic. All kind of things that would suck.
If you can't clear that bar as a manufacturer, you shouldn't be one. You could still build things for yourself – but if you want to sell things to others they should be able to assume you are not out there to kill them without deeply researching your company, aquiring a degree in mechanical and electrical engineering, buying your product and disassembling it. And I say that as a person that would be able to do that, unlike most.