I was wondering if a person prays for whatever reason while not pure or janub, is that a sin itself to stand before Allah and pray in janub or impure state? of course the prayer won’t be accepted and is void but i was wondering if the act itself is also a sin to do such thing.

Example: a person who has been negligence of his salah into his adulthood all of a sudden find himself being religious and want to change but developing habits of it is a struggle especially when he procrastinates and is lazy about taking ghusl to be pure so he can pray. now instead of doing everything at once to be good muslim and burdening himself and then fall off track again and giving up. This time, he instead wants to take a different approach to reform himself which is to focus on one thing at a time and once that becomes habit move to fix another bad stuff in the hopes as time goes by in a year or 2 or 3 he will be proper decent muslim doing all his wajib acts daily without procrastinating and after that he can start doing the lapse prayer along with wajib prayers. The book atomic habits explain this methodology better and I believe this type of baby steps reformation is what Allah used for the arabs. Allah through the course of the Prophet’s mission slowly reform the arab. I mean Allah didn’t just tell the muslims from day 1 to pray fast and do everything. So this is what the niyyah of the person is and the objective to give himself absolutely zero excuses to not pray. In other words even if shaytan whispers and make him lazy to do ghusl, regardless stand for salah even in janabat state. The goal is to go 100 days daily standing for salah to make it an habit to the point where you have subconscious need to do it past the 100 days which then becomes the habit. after or along those 100 days add the fact try to offer more of the salah in state tahira eventually that too becomes always in state of tahira and inshallah conquer this and become a better muslim.

This is another way of Satan's ways to play with him, so he tells him to pray now without purification, so that she can get used to praying. You are now not in a state to wash. These are the tricks of the devil. Trust 100% that he will never be able to succeed, but will remain in this situation until he dies, then he will bite the fingers of remorse.

Can anyone guarantee that he will live one day, to say I will take it easy until I get used to the duties and then I will do them properly?

As for man measuring himself today, after the completion of the Sharia, with those who lived at the beginning of the Sharia, then this is meaningless. Moreover, it is ignorant that a person brings work in a form that he knows is invalid, and that he will be forced to repeat it under the pretext of laziness.
The sane person does not waste his time and expose himself to the wrath of God, and he does not guarantee survival for one moment. There is no doubt that performing the prayer without ablution is forbidden and sinful