The undo tool is commonly used on computers and can be helpful when making accidental changes in Google Ads. In the above example I have reversed some keyword bids, but you can reverse many things changed in Google Ads.
There are some limitations though, the update you have made does not come up in the change history straight away so you may have to wait if you want to reverse something straight away and in a lot of cases the undo button is not present due to other changes that have been made to the account. When it is not possible to undo something, I recommend Google Ads editor if you want to make bulk changes.