It really depends on how you use your macbook and if programs you use require more ram in your computer. at the time of writing this page (2021), we can safely say that 8gb of ram is a minimum requirement for day to day usage of your macbook, however we do have clients that are still okay with their 4gb of ram boards and don't find ram upgrade crucial for their usage. we recommend you do a research on some of the ram demanding softwares you use often and find out if the applications could benefit from higher ram capacity before spending money on ram upgrade. as for upgrading to 16gb or 32gb if possible, it really depends on the type of applications you use and if they rely more on ram.