Battery Replacement. How will it affect my phone?

My iphone 12 has 76% battery health and i want to replace the battery. I want to replace the battery on my own because there are not any repair shops in my city , and I am planning to get the repair kit from Ifixit. Ive seen the correct way of replacing the battery but i dont have a contact welder. My question is: When i replace the battery with ifixits battery and do not calibrate it , where will the important battery message affect my phone? Is it only not going to show battery health(i dont really care about battery health %) , or i wont be able to do anything else?Will i be able to update my phone?Will i lose performance?Someone please help me because i searched many forums and havent found an asnwer.

Will it be worth it to replace it with this affordable solution or the downsides of the replacement are not worth it and i should send it abroad and repair it for around 170euro?