Mr Weasley is seen as a weird oddball for engaging in studying muggle technology. The wizarding world sees it all as a bunch of pointless nonsense that muggles have to go through just because they don't have magic. Clever in its own way, but utterly futile.

Why spend hundreds of people's effort, lots of money and enormous amounts of time to design, make and use a vehicle to go somewhere when you can hop in a fireplace and think about where you want to go, or simply apparate there?

Why carry a complicated muggle weapon around and spend time and effort learning how to use it well, when you can kill someone with two words you've known since you were a child?

Voldemort isn't just protected by being a powerful wizard, he's also protected by the bully's standard protections of surrounding themselves with sycophants who unquestioningly support them (by ruthlessly turning against people who question their authority or judgment), having no moral hesitancy whatsoever and avoiding like the plague fair fights wherever there's a chance they'd not win.

So because of Voldemort's followers who will turn up in an instant and his horcruxes, you have to be prepared to sacrifice your life to have a chance of opposing him openly, which is of course what Lily Potter did.

Strange that JKR, who clearly didn't like bullies, would choose to bully trans people and use her money and influence against them. Admittedly she clearly had a bit of a problem with blonde people before she wrote book 1, so not exactly completely free from prejudice.

Pretty sure wizards are familiar with old technology like trains and cars. But like another comment said, muggles are advancing while wizards stagnate in their old ways and traditions and shit since they keep themselves so separated.

For all we know the hogwarts express runs on magic and so does the car, after all it flies.

Combustion, sure, but not an explosion. Or the car is a special magic car or whatever.

No one thought to make magic bullets to counter protego charms?

I don’t remember which book but I also have this clear memory of a quick passage saying all the magic around them was messing up with electronics.

Also I’m pretty sure in the Deathly Hallows they use the internet to follow Death Eaters sighting while they are in hiding

(Been a while… and I’m not bothered enough to go check 🤣)

Also Arcanum a CRPG by troika, there's a newspaper you can find where someone tried to put a fire enchantment on a musket took out a city block.