Now angry rant time
I can understand the laws but I absolutely despise the attitude people have towards age gap.
It should be like "okay well at some age, the probability of informed consent falls too low to risk and we're not sure about the threshold or where to draw the line and all. So we're gonna make a guess with our intuitions and from that, create a rule that will hopefully work for the average person." The law is merely a method. It does not dictate right or wrong. If it did, then apparently what is right or wrong will change simply by moving a few hundred km in a particular direction... which doesn't make sense since ethics is universal.
Instead it's like "AHHHHHHHH!!! PEDOPHILE!!! PROTECT THE KIDS!!!! AHHHHHHH!!!!!" while the 'kids' are like "bruh wtf we totally said yes. Like, bitch please we're going through puberty and we wanna do stuff and we're not stupid. Matter of fact we're probably better informed about this shit than half of you dipshits are. Like seriously there's two people in the relationship and you're fucking tunnel visioned on one." (Disclaimer: I can't actually speak for other teenager's attitude, only myself when I was about 15 and a few friends.)
Age gap relationships are stuff that should be tread upon with some extra caution perhaps, but that does not make them wrong. I hate how society vilifies the older person in these relationship and victimizes young person. Fucking assholes pass judgement on other people for doing their own things and calls them ill/disgusting or ignorant and unable to make a decision. Cuz 3 years is gonna make all the fucking difference right? And 18 year old people are leagues better than 15 year old people.