It is Amazon Prime that dropped support for older Roku models like your 2XS, not the other way around.
Amazon announced in emails to Roku owners this fall that, effective November 1, 2021, their Prime Video would no longer support the following older Roku model numbers:
Roku 2 HD/XD/XS models 2050X, 2500X, 2720X, 3000X, 3050X, 3100X Roku LT models 2400X, 2450X, 2700X Roku SE model 2710X Roku Streaming Stick models 3400X, 3420X, 3500X
(The Xs or other letters at the end of the model number are distribution codes and are irrelevant for this issue.)
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