I never played COD before (so I had to make a spreadsheet of all the weapons). I only played pubg, first on PC then xbox.
Blackout is fun, more fun than pubg in many ways. You can land at any compound and get decent enough loot to fight immediately, usually in the first house. That is a breath of fresh air.
Sound is very loud when someone is close by, there is no "stealthy sneaking up". There are fun gadgets like the recon vehicle which is so much fun to drive around.
You find fights fairly quickly, the games are shorter, the action is quicker. The FPS is fast, the fights fair.
What is doesn't have is pubg visuals, that mountain view sniping down on the valleys below. Or flying to the west side of Erangel to take a motorcycle ride down the coast to the seaside town. It doesn't have the same tension, you know someone is near, with pubg you just don't know when you are going to run into someone.
It is really two very different game styles, different experience. Not sure if I will come back to the longer, quieter pubg games, I assume xbox one x is still broken?