Good condition T-64s would still be devastating platforms for engaging Styker-type and BTR-type vehicles. While the poor armor is very vulnerable to even lighter shoulder-fired weapons the T-64’s main gun with modern ammo is a threat even to today’s tanks.
At Fort Benning we wargame against OPFORs with obsolete CCCP vehicles and especially in an urban environment Blue losses can go quite high against those systems.
Perhaps Thailand would prefer diesel engines as there are some advantages.
T-64 was a complicated nighmare. Cost and maintenance problems were a primary reasons why it was replaced with much more primitive T-72 with Soviet military, initially designed for Third World customers.
T-72 was priced at 340 to 420 thousand rubles for domestic market at the time and T-64 was 830 to way over million.