Battlefield 4 surpasses Battlefield 3 from a gameplay perspective but falls behind in terms of it's aesthetic, and single player offerings, as well as some frustrating multiplayer imbalance.
Battlefield 4 plays leagues better than BF3 does, with the game feeling much faster and more fluid than its predecessor. With more weapons, vehicles, and customization than Battlefield 3, Battlefield 4 is easily the go-to if you want to play a modern day Battlefield title. That said, you have to get around some of the more infuriating realities of multiplayer. Those being: vehicle mains getting 100+ kills in Attack Helicopters, Tanks, and Jets. The Mobile and Base AA are also problematic, with mobile AA having incredibly long range, and the AI controlled AA gun being easily exploited by lesser skilled jet pilots who can't win dogfights.
Battlefield 3 remains superior in terms of its gritty aesthetic and its single player offering. BF4's graphics often look too shiny and reflective compared to BF3's dusty feel. That and I prefer BF3's blue screen tint over BF4's piss filter. Battlefield 3's campaign also offers a better story than BF4's weird virtue signaling thing they had going on with Irish and Hannah's forced rivalry.

Battlefield 4 is arguably the best Battlefield infantry experience you can get!

It had a disastrous launch and it took DICE LA (not the developers) years to polish it out. The movement system is fast and fluid, combined with addictive gunplay. There are some exploits like ZouZou jumping which take some time to practice but can make the difference in most situations. There are tons of HUD customizations and this should be mandatory for all FPS titles but you won't find it outside BF4. I started playing it actively back in 2017 and I have spent 300+ hours playing mainly Operation Lockers 24/7 and other good infantry maps.

From here on, everything goes downhill. Battlefield 4 is FULL of annoying gadgets, grenades, etc. Most of the maps are terrible or made for vehicle combat where a good pilot/tanker can dominate the entire enemy team. Before it was full of terrible admins who would ban every good player because of "cheating". Currently, most good servers with proper rules and weapon/gadget restrictions are offline so It's a lot harder to find a proper server.

Battlefield 4 is also the last "good" Battlefield title. Everything after it has been a shitshow and DICE is trying to attract casual players and forcing political correctness, Swedish style. I'm a fan of the series ever since Bad Company 2 where I spend 1000+ hours. I pre-ordered Battlefield 3 (where a lot of bad changes were implemented like suppression), Battlefield 4 and Battlefield 1 (which I couldn't play for more than 100 hours). After so many disappointments, the whole franchise is dead to me and I couldn't care less for the future titles.

I was at a weed dealers house in college and he was playing this. He passed the controller to me and after I played for maybe fifteen minutes, a friend of mine started puking uncontrollably after eating an edible. We then took him outside cause he was covered in puke and wouldn't stop. As we're cleaning up we heard him laughing outside. Upon checking on him there were like five raccoons huddled around him and one on his lap eating the puke off his shirt. We shooed them away and he said "Why'd you scare them away, they were warm."