Syndrome's plan makes no sense
It does make sense all the way until '..and when I have had my fun, I will sell them'.
If he sells the 'super gear', so 'everyone can be special', which in his book means, 'no one will be', there are going to be enormous, upheaval-sized consequences.
What will happen, when the 'haves' can have super gear, and the have-nots can't? This gear would never be exactly cheap, being high-tech and all.
Of course crime would become rampant, the 'have-nots' would simply at least attempt to steal as much as that tech as possible, and undoubtedly at least some of them would succeed, then they could use that to take over. Cops would be equipped with this stuff, but then, so would be criminals and regular people - everyone would be flying into walls and zapping each other while enormous crime sprees swipe the planet, and people would die by the thousands.
Too dramatic?
Ok, let's tone it down a bit - no one will immediately zap anyone, and people will use the equipment 'responsibly'. Hard to imagine, isn't it? But let's try anyway.
So, who wants to work normal jobs anymore, if they can just fly around and do whatever they want? I mean, if you can either work on some b*tchy housewive's plumbing and house repairs, or you can just swoosh all over the place and do something that requires super strength and flying ability that you couldn't do before, etc..?
I don't have to finish that kind of questions, do I? It would imbalance and repurpose most jobs, and it would make people stop being 'peasants' when they can be 'superheroes', and become rich.
It's the same kind of problem as giving everyone a million bucks - who would do some janitorial duty for tiny pay if they have a million bucks? The problem is, the million would become worthless, because everyone has got it, and so on.
The implications of selling the supergear are just ridiculous - how is any rich individual going to feel safe, when crime gangs can just fly into their garden, kill them and take anything they wish?
How is Syndrome going to ENJOY his retirement, when he has to live in a world where money suddenly can't buy everything (or almost anything), where he could not be safe (well, the volcanic lair seems pretty safe, though), where he couldn't just live a leisurely rich life, but he'd have to see 'superpeople' everywhere, wrecking everything and flying into walls (if it can happen so easily to Syndrome, surely some amateur Gen Z tiktoker would be almost guaranteed to slam into something and kill themselves that way)..
He would have to spend his retirement in the world of chaos and crime, where his money wouldn't matter as much as it otherwise would have. This plan would never work.. you can't make everyone super, and then expect the ony effect to be '..no one will be'.
The power dynamics would be turned on their heads, when a 'flying super squad' could attack a military base and steal tanks, destroy jet fighters and so on.
What about other countries that don't have these things? How easy would those countries be to control, rob, etc.. mafias would rise again and hoard these devices, and there would be massive wars about who controls all this tech. You can't just 'sell' it to the unwashed masses and expect things to continue just fine.
As no one would take care of the menial, grindy, important jobs, infrastructures would collapse, toilets would cease to work, food production would halt, factories would be blown up and so on.. this kind of plan makes absolutely no sense.
Put a monkey into a laboratory and see what happens..