Depends on how you define heavy.

The minimum basic requirements are higher than Windows 10 but very few people are using computers with the Windows 10 minimum in 2021 and haven’t for years.

The 64gb minimum hard drive space is needed only for during installation and the storage of the Go back files which are deleted after ten days. Once installed and the Go back files are deleted, the basic Windows 11 system files actually uses less disk space than Windows 10.

I did some unscientific comparisons of memory and disk space use between Windows 10 and Windows 11. I did clean installs of each on separate SSDs on the same computer. For the memory comparison I reduced as much as possible the processes running to the minimum needed and I disabled all Startup apps, so that they matched as best as I could get them and used Task Manager to display the results. I found that Windows 11 uses slightly more memory than Windows 10 (about 200mb).

For the disk use comparison, after cleaning up, I measured just the total system files (Program Files, Program Files (x86), ProgramData and Windows). I left out Userfiles because the difference was negligible. Both were under a gigabyte. I found the total disk space used was substantially less with Windows 11 than Windows 10. There are fewer folders and fewer files. I assume this is because Microsoft has removed a lot of legacy components that it’s no longer supporting or are no longer used such as support for 32 bit CPU’s.