illustrator version 24 vector file is too large
Windows 7 Pro - Adobe Illustrator 24.0.2 (2019)
Opening a 2.7 MB Adobe Illustrator 23 (2018) all vector file and saving it.
Expect file size to remain similar or the same
File size of the new version 24.0.2 results in 260 MB
The file is using Gaussian blur. I suspect it is this. The file attached is the 2.7 MB version 23 file.
This happens most probably because of the enabled PDF-compatibility option on save, which makes Ai write a PDF copy into the file along with the native Ai format. It helps to other apps to place and use the artwork inside, but it also makes the live raster effects to get rasterized, and it leads to size bloating.
Untick the 'Create PDF Compatible File' option and the file size will stay at 1-3 MB.