Attachment size limits

I can't figure out any reason why there would be different limits for different attachment file types. Why is the limit on .xlsx only 1M but a .xlsb can be 9.7M? And so on.

Can't we just have one limit of 9.7M (or an even 10) for everything?

Filetype	Max File-size
bmp	100 KB
csv	1 MB
doc	1 MB
docm	1 MB
docx	1 MB
gif	100 KB
jpe	100 KB
jpeg	9.77 MB
jpg	9.77 MB
pdf	9.77 MB
png	9.77 MB
txt	100 KB
xls	1 MB
xlsb	9.77 MB
xlsm	1 MB
xlsx	1 MB
zip	9.77 MB

I will ask the TT for clarity on this.

For future use : good to know that a xlsb is 9.77 !
Thanks.

When you click on "Manage Attachments" it shows you the list I gave.