pretty much, this is what french tank designers went with during the cold war. Tiny shitboxes with paper thin armor and huge guns and engines and sometimes missiles. The french MBT also follows this trope as its the fastest mbt in service and hold multiple tankathlon shooting records

I think something important to note with regards to the question of tanks' continued relevancy is: relevancy in what role? As the main battle tank, by definition, fulfills a bunch of different roles, its relevancy could be different depending on the role we're talking about. In the mechanized offensive role, indeed tanks face a lot of issues and are highly vulnerable - the reason why Western tanks are so heavy is precisely because they've realized how vulnerable tanks are, but are essentially stuck in the bargaining stage, continuously strapping on more and more armor and other upgrades, and kind of skipping over the question of "yeah, but how many of these fancy tanks can you actually field, given how much they'll cost with all these features?".

For the infantry support role, however, tanks are still relevant - during assaults, you'll always want to have some kind of cannon so you can fight harder targets, like bunkers and the like, and because indirect fire support is slow, difficult to coordinate and not necessarily the most accurate, you'll want the cannon to be on a vehicle so it can actually get close enough to the target for direct fire, and if you're going to be approaching the enemy, you'll want armor - and thus you've just reinvented the tank. The only thing that could truly make them obsolete in this role would be massive advances in the capabilities of indirect fire support - and admittedly, advances are happening, artillery has improved massively in range and accuracy, missile technology has allowed the development of a new form of artillery which can be even more precise (but admittedly, also a lot more expensive), and the profileration of drones now allows artillerymen to directly observe their targets, instead of having to rely on a guy kilometers away calling them on the radio, holding a crumpled map and trying to figure out which coordinates the enemy is at. So one might envision a future scenario where a high degree of digital integration and automation allows soldiers to actually do the Call of Duty thing of pulling out a little tablet, pointing at a target on it and having ordnance immediatelly delivered from cannons kilometers away, but sci-fi stuff like that is probably still a long way off, if even possible.

This predicament, however, entirely vindicates Soviet rather than Western tank design - making a tank that doesn't have all the fanciest capabilities, but is good enough, cheap, simple, reliable, something you can make a whole lot of, so that you have enough to attach a few to every infantry brigade and give them organic fire support capabilities. Westerners love to mock the Russians for pulling out various older tanks - except that for supporting infantry, those older tanks, with a few upgrades, are quite alright, and the key thing is that the Russians actually have equipment to pull out of reserve. Western militaries other than the US have absolutely fuck-all - most of their tank fleets are like 200-300 at most, and as this war is showing, you will suffer losses, it doesn't matter how fancy your wunderwaffe tank is, it's still going to get blown up. And if you have barely 300, your military industry has been thoroughly neoliberalized and can barely even make a dozen tanks a year, and those tanks are dependant on highly complex and fragile supply chains which will inevitably be disrupted in the event of a global conflict (and how much would these tanks really be worth without all their electronics and optics?), then... you have basically no means to actually fight a protracted war, your equipment will dry up in a month and then you'll just have nothing. Perhaps the Western obsession with fighting lighting-fast "shock and awe" wars is because they, deep inside, realize that they have no capability to actually fight a serious peer conflict for more than like a few weeks.

I doubt they'll be able to take that much weight off - the original pre-A1 Abrams was already 54 tons. I'm not too familiar with bridge weight limits, but the Japanese needed to bring their newest MBT down below 50 tons in order to make it viable for 84% of their bridges.

America currently has 1 (one) factory that is located in Akron, OH that manufactures somewhere from between 1 to 12 M1 Abrams tanks per year. To get the new ones, you’re going to have to wait a little while longer.