Do near field monitors require vibration isolation?
The answer is NO!
Vibration isolation wasn't even a thing for reference monitors. But now they're everywhere.
The Owner's Manual of the most popular reference monitors make no reference to vibration isolation.
Reference monitors always have a rubber ring around the cone of the sub woofer. Therefore there's dampening in the most needed areas.
Metal spokes suspend the sub woofer on the inside. This adds an extra level of separation.
There's cloth insulation lining the inside of the cabinet. Hence absorbing all remaining vibrations.
The inside corners of monitor cabinets have cork wedges glued to them. This further dampens vibrations.
The Pro Audio industry has always taken your money for things you don't need. The vibration isolation field is no different and there are a ton of options. Perfectionists will always set up a vibration free room. But they'll never record an album or a single complete record. It's easy to take your money in this world, is the point.
Buy what you need, and what makes sense to your physical space. Equally important, get sound down into your DAW as quickly as possible. Once you're in the zone and a few records deep, you can fine tune your studio to the fine ears of Hans Zimmer. Until then, you don't need vibration isolation pads or expensive decouplers.
Where is speaker isolation necessary?
Expensive Home Theatre Speaker Systems can shake the floors they're sitting on. Therefore it would make sense to isolate those, but not desktop speakers. Reference monitors simply don't get loud enough. So they don't require vibration isolation.
Aligning tweeters with your ears is the most important effort you can take to get the most out of your reference monitors. For example, Soundrise Pro speaker stands raise your desktop speakers by 9" and open room underneath for more gear.