Hello 👋 I hope my response answers your question! The difference between these two negative adjectives is the level of annoyance you want to express; time-sucking is more negative than time-consuming.

There is a difference. Time consuming is not as negative as time sucking. However we don't use "time sucking". We say "sucking the life out of me" or "draining me". Time consuming means it takes a lot of time to accomplish/to do something. Example: This is a very intricate and time consuming job/activity/hobby etc. This job is sucking the life out of me. OR This job is draining me slowly. These two sentences are way more negative than time consuming. You can do a time consuming activity that you still enjoy beacuse of the results you will get.

Generally I think they are both the same. Maybe a task that is time consuming just takes a long time but you don't necessarily not enjoy it. When something is time sucking it's like sucking the life out of you. Sucking the life out of you means like you feel its just leaving you with nothing kind of. However I don't use time sucking. Examples: 1) The project was very time consuming. 2) My work is very time consuming. 3) The recipe was very time consuming. 1) This job is sucking the life out of me. 2) My day to day is always the same it's sucking the life out of me.