Remove HTML In Google Sheets Cells

You can just use a Find and Replace dialog.

Find what: </?\S+[^<>]*>

Replace with: <empty string>

Search: Specific range = '<SHEET_NAME>'!<COLUMN>:<COLUMN> (e.g. 'Copy of Sheet1'!A:A)

Make sure Search using regular expressions is checked. Then, click Replace all.

Here is a screen: