The problem with banning these is that most of the time, the victims aren’t being forced to go to these places. Adults are talked into it using whatever religious shaming bigots can come up with.
When it comes to kids, you run into the issue that kids don’t have a say in their own lives (they do have rights, but they can’t easily exercise them). You can ban discrimination based on sex or gender, but you can’t easily interfere with a week-long church program for troubled youth. The state doesn’t get to dictate your religion.
A significant portion of just about any country on earth is grossed out by the thought of homosexuality. For a large part of voters, being gay was still a crime back when they were young. Things like gay marriage are still hot topics in the EU today. On the scale of centuries of backwards abuse and scapegoating, gay rights have moved forward at lightning speed, and it’ll take a few generations for those advancements to solidify (or, in case of the US and UK, lose decades of progress to hopefully regain them in the future).
Also, leeches are still used in medicine today, as well as ants, worms, and maggots. Not to cure the flu (unless your flu symptoms are the result of extreme iron consumption, in which case bloodletting is still necessary and leeches may keep blood flowing while doing that).
I always thought these markings were made by machines, until I saw some people draw them by hand. Turns out, you can make near perfect road markings with a movable can of paint. If you use GPS to trace out your track, you can just fill them by hand.
As for construction, here’s a timelapse of making one using stone tiles: https://youtu.be/gXiOt-9WCag
Here’s one made of asphalt: https://youtu.be/DORBEGYVgYE Note the pre-poured blocks of concrete in the center, which likely help the round shape.
In this video you can see the imperfect temporary road markings for a short moment: https://youtu.be/SV2vSL_hiA0
This video showcases a different style of roundabout that makes two-lane roundabouts a bit easier. Note the two round, concentric lanes separated by concrete barriers: https://youtu.be/iRclLOgN-xw
This video showcases the manual driving work done to make the round roads: https://youtu.be/KCQv24BkI6Y This is a four lane roundabout. The video also shows how the line markings are applied (by a spout, in a car).
This video shows a prefab concrete roundabout installed over a weekend. All they needed to do was prepare the soil, lay down the blocks and paint the lines: https://youtu.be/J-BZWfbygkc
This video shows how the center concrete slabs can be laid on location using a specialised machine: https://youtu.be/J2g0JZzqbAs
I’m not sure if this tech is applied, but farmers use millimeter precision GPS to efficiently farm their soil. The GPS receiver itself costs a couple of grand, but making a car in a closed-off road drive in a perfect circle is hardly a technical challenge these days. That said, these people can probably do it by hand and you wouldn’t notice the difference.