It's a story as old as time. Armored thing hard to kill till it isn't. Now one infantryman with the right missile or one drone equipped properly and tank is done. . It's got every 1st and second world nation terrified. The Ukrainian are stripping parts and batteries out of totalled electric cars and making cheap suicide drones that can fly or navigate on water fast enough to ram into planes, ships and tanks and carry enough explosives to take them out of the battle.Tank meets drone.
(Yes, high quality armor is expensive, yes, it does work.)
To give you an idea of how bad it is. The Russians have lost 3000 tanks and 9000 other armored vehicles this year so far.
They expect to produce about 1500 tanks and 3000 armoured vehicles a year. So the Ukrainian are blowing them up twice as fast as they can be replaced at a fraction of the cost. When you start talking about planes and ships the monetary losses and time to replace them gets far worse. Drones may replace artillery as the King of Battle before this is over And infantry has once again taken its place as the linchpin of the army. And the scary thing is that this is all being done with normal easy to access supplies and technology. The time of quick wars to prove your point may be over for the foreseeable future.
But it's just the modern version of what played out in ancient history. Technology makes someone king till it becomes cheap and Ubiquitous and then suddenly the king isn't unbeatable anymore.