The US is not doctrinally representative of most militaries because it is almost exclusively focused on expeditionary fighting far away from its shores. The USMC is the most expeditionary arm of an expeditionary force so it is in particular a poor representative of world wide armored doctrine. Everything the USMC, and to a somewhat lesser extent, the US military, procures is expected to be transported by plane or ship to a warzone far away from the US.
If you look at land powers who actually expect to fight a serious peer-level land war, there is no overall discernable turn away from the MBT. Russia is still developing the Armata family (even if war time circumstances prevent Russia from adopting it), China has recently adopted the Type 15 light tank and is still allegedly working on upgrading the ZTZ-99A. India hasn't abandoned the Arjun and has made no moves towards pivoting away from buying T-90s from Russia. Germany has (just last year) sold Leopard 2 upgrades to Sweden and Italy, and Rhinemetal has presented prototypes for upgunning the Leopard 2. Britain committed to upgrading about 150 Challenger 2s to Challenger 3s in 2021. Japan adopted the Type 10 in 2010. South Korea introduced the K2 in 2014 and is apparently selling them to Poland.
You might reasonably argue that many of the above pre-date the lessons of the Ukraine war, which is a fair point but none of these systems have been cancelled or further procurement delayed or replaced. Similarly, talk of missile based light vehicles to replace tanks have not really gone anywhere either so there's not really any basis to say MBTs are becoming obsolete.
You might recall that there was a very similar debate during the Cold War which said that MBTs were obsolete because of ATGMs only for new composite armors, ERA and APS to significantly degrade ATGM performance.
The US is not doctrinally representative of most militaries because it is almost exclusively focused on expeditionary fighting far away from its shores. The USMC is the most expeditionary arm of an expeditionary force so it is in particular a poor representative of world wide armored doctrine. Everything the USMC, and to a somewhat lesser extent, the US military, procures is expected to be transported by plane or ship to a warzone far away from the US.
If you look at land powers who actually expect to fight a serious peer-level land war, there is no overall discernable turn away from the MBT. Russia is still developing the Armata family (even if war time circumstances prevent Russia from adopting it), China has recently adopted the Type 15 light tank and is still allegedly working on upgrading the ZTZ-99A. India hasn't abandoned the Arjun and has made no moves towards pivoting away from buying T-90s from Russia. Germany has (just last year) sold Leopard 2 upgrades to Sweden and Italy, and Rhinemetal has presented prototypes for upgunning the Leopard 2. Britain committed to upgrading about 150 Challenger 2s to Challenger 3s in 2021. Japan adopted the Type 10 in 2010. South Korea introduced the K2 in 2014 and is apparently selling them to Poland.
You might reasonably argue that many of the above pre-date the lessons of the Ukraine war, which is a fair point but none of these systems have been cancelled or further procurement delayed or replaced. Similarly, talk of missile based light vehicles to replace tanks have not really gone anywhere either so there's not really any basis to say MBTs are becoming obsolete.
You might recall that there was a very similar debate during the Cold War which said that MBTs were obsolete because of ATGMs only for new composite armors, ERA and APS to significantly degrade ATGM performance.