Because it is still good though.

If you have a good product, you are more understanding. And getting worse doesn't mean its no longer valuable, only that the price/value factor went down. But Opus 4.5 was relevant better and only came out in November.

There was no price increase at that time so for the same money we get better models. Opus 4.6 again feels relevant better though.

Also moving fastish means having more/better models faster.

I do know plenty of people though which do use opencode or pi and openrouter and switching models a lot more often.