Neither side has been able to establish air superiority, a testament to the anti-air weapons both sides are deploying and without air superiority there isn't going to be any major breakthroughs based on maneuver.Unfortunately. combined arms doctrine, to be used effectively, needs both the equipment and years of training and practice practice practice. It's not something where you just shovel in the equipment and expect it all to come together in a year. Ukraine has been moving away from Soviet doctrine, not least building up a strong NCO ethos, as well as training junior officers much closer to NATO doctrine, but a lot of the senior officers are still somewhat mired in the old Red Army days. They are getting their, war is a harsh teacher, but it's slow and it's painful, and with the advent of drones, a lot of the old doctrine is having to be rethought.
As for Biden dragging his feet, they've been trying to "give Putin an off-ramp," ie persuade him to back off and just keep what he's gained, but all that dies is feed the beast. Never forget it was Obama who gave Putin Crimea, and Biden who said it was okay to take more of the Donbas, thereby encouraging Putin to attack. It was also Biden who offered Zelensky a ride out, expecting Ukraine to collapse and not expressing too much concern about it. He then slow-walked aid and is still slow-walking aid. We could send another 500 Bradley's and ten Patriot systems tomorrow without even missing them. Ditto F16's and A10's. They're just sitting there....
Some think the f-16's are going to make a huge difference...........they aren't.