I currrently live in UK as a spouse with leave to remain residence permit which is expiring in May 2021. Due to personal reasons, we have decided to move from UK. So I will not be applying for a further leave to remain spouse visa extention. Is there anything I need to do before I leave in terms of informing home office? What does this mean for future visit visa applications? I have some money saved in my bank account, would my account be impacted by my immigration status?
You do not need to inform the Home Office, or any other government agency, about anything at all. There are no 'exit visa' or other exit conditions (barring obvious legal difficulties) in the United Kingdom. As far as your future applications are concerned, in theory it should have no effect. But in reality if you've followed all of the rules and left before the expiry period of your previous visa, it will be taken into account generally positively - though that can highly depend on what reasons you are trying to return and how genuinely you express those reasons.
About your bank account, it will most likely not be affected at all (assuming all current typical industry laws and policies stay the same). But there may be all sorts of local laws with regards to your country of origin, or your country of new residency, that you may have to take into consideration.