The question isn't 'Which one?', it's 'How much budget goes to each?'. Google Ads is the ocean; it has 90% of the volume. Microsoft Ads is the private pool; it has 10-20% of the volume, but the water is cleaner. Microsoft Ads typically delivers a 30-40% lower Cost Per Click (CPC) and often a higher Average Order Value (AOV) due to the older, wealthier demographic. Smart advertisers maximize Google until diminishing returns hit, then pour the excess budget into Microsoft to capture cheap, high-quality conversions.
Microsoft makes this easy with a 'Import from Google' button. We use this as a starting point, but we never leave it on auto-pilot. Bids and negatives need to be adjusted for the different user behavior on Bing.
It is nearly identical. If you know Google Ads, you will feel right at home in Microsoft Advertising.