Over the ages, what used to be regarded as joseki, went out of fashion or was discarded in the light of new developments. There are a number of reasons why a joseki variation would be discarded:
- Improvements/Fashions in Go Theory: e.g. the joseki is not efficient, or the joseki is superseded by one placing more influence on the centre.
- Improvements in tactics: e.g. turning inwards in the large avalanche.
- Changes in rules: e.g Introduction and changes to komi  - A joseki that results in an equal exchange of territory is likely to be rejected by Black as being too slow. Black may prefer something more dynamic, such as an exchange of influence for territory.
- There would also be the situation corresponding in languages to expressions that are no longer idiomatic: the plays are quite comprehensible to pros, but somehow don't fit with a current way of thinking. See the developments in Global joseki.
- Sometimes joseki fall out of fashion for no apparent reason and are revived, either structurally or occasionally.
- catenaccio joseki
- aigosumi joseki
- Large avalanche - jump in
- the inward turn of the large avalanche joseki
- joseki moves discarded by AI
 It's interesting to observe that patterns like the aigosumi joseki, played in the era of no-komi go, was rejected then as too slow and is being tried again as komi increases. With no komi White has to try harder with more severe or even risky moves. On the other hand, as komi increases White seems to feel able to relax a bit. But of course there is also the effect of giving komi on Black. Now Black has to play more severely whereas before it was, perhaps, possible to relax a little. See also The Psychology of Komi.