不如【bùrú】

A 不如 B means A is not as good as B. On its own it compares overall; an adjective after B names the quality.

不如 always leans towards B. The adjective names something good that B has more of – 好, 快, 便宜, 方便, 漂亮.

• × 这个房间不如那个脏 → 这个房间比那个干净
• × 我不如他很高 → 我不如他高

Might as well

After a clause describing a poor option, (还)不如 + verb phrase puts forward a better one: "you might as well", "it'd be better to".

The second example pairs it with 与其 "rather than", a fixed frame with its own point.

不如 or 没有

没有…那么 and 不如 both mean "not as". 没有 is neutral and takes any adjective; 不如 adds the judgement that B is the better one.