Why not just use the latest version of MAME? There are two main reasons: Performance and Compatibility.

Even with the right romset, you might run into issues. Here is how to fix them:

This is where most beginners get stuck. You cannot simply download "Street Fighter II" and expect it to work in every emulator.

Arcade games are complex. They often require multiple files (parent ROMs, BIOS files, and sound samples) to function. The organization and naming of these files change with different versions of MAME.

If you try to use a ROM designed for MAME 0.220, it will likely fail to load in MAME 2003-Plus because the emulator is looking for specific file names and checksums that were standard in 2003, not 2020.

In RetroPie:

While MAME 2003 Plus is excellent, it is not perfect: