The main reason BF4 is as praised as it is is because for console players it was the first time a Battlefield game had 64 players. Same thing with BF3 tbh, if you played on consoles it was your first mainline Battlefield game. BF3 and especially BF4 (PC peak was like 40k, whereas BF1's PC peak was over 100k) were wildly less popular on PC than the earlier BF games. They're both pretty bloated and mediocre imo, but for a significant portion of the playerbase they were very novel experiences.
I don't feel that way. Perception wise, there are less transportation vehicles like jeeps that help get to farther objectives quicker, but I don't think the maps have gotten big enough in BF5 that it effects gameplay in a negative way. In fact, I like the bigger maps because it allows more varied combat engagements and I don't feel like I am forced to join the meat grinder. Of course, that's my personal preference so I don't expect you to share that same opinion, but each class should be supporting their squad at the micro level and team on a macro level, and in doing so, should take advantage of the support that player can give based on the class role chosen.
The maps are definitely more open outside of a handful of maps like Sinai or Hegioland.
On most of the "big" 3/4/1 maps the maps may seem really open, but the flags themselves are all in a skyscraper or parking lot or some other small place where everyone has to get in each others' face to cap. Looking at BF1 maps, which a lot of people complained were too open: When you arrive at flag C on Empire's Edge, where is the fighting going to be? Inside those two towers. Amiens E flag, where are the enemies? All bunched up in cramped alleyway. Ballroom Blitz C flag? The bunker caps that make up the bulk of flags on Argonne, Monte Grappa, Verdun Heights, etc.? Basically all of Fort De Vaux? The miscellaneous towns, trenches, and other cramped environments that make up the flags on Giant's Shadow, Suez, Soissons, Nivelle Nights, etc.? All CQC flags.
BFV's flags by contrast are pretty large, you can cap from outside the range of an enemy's smg.