This topic is a bit more complicated than an outside observer would be able to pick up on without perhaps doing a bit more research. One common misconception people from other countries seem to have is that all the change is being made at the federal level. In fact, quite a lot of legislation is produced from smaller jurisdictions, and gun legislature changes frequently, and becomes more strict over time especially in heavily populated areas like Chicago, Seattle, New York City, their respective counties, etc. Keep in mind, the US is larger geographically than all of Europe, so there's a lot of diversity in issues and ideals across the states.
Gun reforms at the federal level are complicated. There is a large portion of the US (at least geographically) that is vehemently against a gun reform, or additional legislature on the subject. And not that this conversation has been about the subject of a nationwide gun ban, but often enough that's where these conversations lead so I'll just take it there -- there's a real concern that a national ban of guns would increase the frequency of gun related violent crimes. Guns are such a large part of the culture here, and so many people have them, and would likely not return them in a ban scenario but rather hide them, that the people committing violent crimes would be more unopposed than ever. We would hope that the people committing such crimes wouldn't suddenly become more ambitious. Couple that concern with the general lack of confidence in our police force. Generally in an active shooter situation, the police are arriving on scene 5+ minutes after casualties have already started piling up. Or in the case of someone threatening your life, the police can't really do anything about it -- often your best bet is just to file a restraining order... which of course doesn't stop a person from assaulting you.
A common thread amongst gun advocates seems to also be that restricting the ability for law abiding citizens to acquire guns is not an effective counter to gun related crimes. If there's one thing that the Mexican drug cartel has made clear, it's that if there's a market for the trafficking of illegal objects, they can be smuggled en masse into the country and be sold to people that are clearly willing to break the law. I think this argument holds some merit, and I say "some" because of course there are gun crimes committed with legally acquired guns.
My disclaimer of bias is that I am a legal gun owner, but I am for gun control legislation. I am agreeable to things such as required universal background checks on gun purchases. Background checks are already required by the federal government for store gun sales, but background check requirements from private sales (person to person) vary from state to state. I am not against a national gun registry. I am not against the restriction of types of firearms that are used disproportionately to commit violent crimes as long as there is a probation period where the new restrictions are measured for efficacy. What I am personally against is what I see more commonly instituted, which is legislation that is purely reactionary and pushed by people with a lack of knowledge on the subject. I talk to too many people about gun control that are familiar with the terms "bump stocks" and "binary triggers" and wanted them banned, but they couldn't even tell me what these things were when asked. I talk to too many people that think I could just go to a gun store and buy a full auto machine gun, which is also false and would be federally illegal. This is just to say, gun control is a topic of much ignorance (from both sides of the fence.) I think it is equally ignorant to be universally against gun control measures, but unfortunately I think their ignorance is at least somewhat valuable in fighting off the ignorance from the other side. I wish that our elected officials were more likely to talk to experts on a topic before proposing what they might propose, but the unfortunate truth is that they don't, and often need reining in.