Hey there! So it's really hard to say one way or another whether or not you should get one, because it's ultimately up to you and your tastes. I would say that it's a great value personally and one that I would recommend if you have the finances and desire.
The PS4 has much more than mature and violent games. Yes, it has its fair share of them, but the console is not limited to them. In fact, most of my favorite games are rated T or below (and you can check them out by clicking my signature). On the system you can find anything ranging from children games like Disney Infinity to mature ones like Grand Theft Auto 5. There's a bigger selection of games for PS4 than X1, Wii U, or Switch (not disparaging those consoles, I'm just talking numbers). So in short, there is something for every type of gamer on PS4.
There are many platformers that give a Mario feeling to me. Some of them that come to mind include the LittleBigPlanet series (exclusive to Sony), Dust: An Elysian Tale, Shovel Knight, and more. There are also more open world platformers that you would be doing yourself a disservice if you don't try like Uncharted/The last of Us (however those games are very mature), Tearaway Unfolded, and Ratchet & Clank. All of those listed are exclusive to the PS4. In the future we'll be getting more remakes of older PS2 platformer titles such as Jak and Daxter and Crash Bandicoot. Yooka Laylee was just released as well which is a collectathon much like Super Mario 64.
Same! I was literally in the same boat as you before I got my PS4 in November of 2014. After the PS2/Gamecube era I got a Wii, 3DS, and Wii U, totally ignoring the PS3/360/PS4/X1. I finally got the PS4 solely because I wanted to play KH3 on it. Similarly, I then bought a PS3 a few months back solely to play 1.5 and 2.5 (this was before they were announced for PS4 lol). I don't regret my decision for either purchase as I've had so much fun out of the systems. I enjoy both cartoony/silly and mature/serious games and this system has all that I want.
In fact, I don't even mind that piracy is unavailable for the PS4 as I've been legitimately having more fun with the games that I pay for than I have with the Nintendo games that I pirated. I'm not saying that you'll have the same experience, I'm just sharing my own. I think that the system is a good value and I hope that this post helped you get a little closer to making a decision.