Ask HN: Is it worthwhile to invest in good chair and table?

I am a software developer and have started doing full time work from home (WFH). I do not have furnitures at my home, just a mattress lying on the floor. There is one cheap plastic chair which is not very comfortable and a table which is only 3X2 feet. Mostly I work on the mattress itself with my laptop. It isn’t very uncomfortable since I am frequently changing my posture. I am 25, so it might be a good idea to be health conscious right away instead of waiting for some ailment. Is it always a good idea to have nice chair and table to work at home irrespective of whether you are full time WFH or not? And did you notice any visible difference in your health or mood or work efficiency?