In my checkered audio career I worked for two different (and well known) wire manufacturers. One leaned toward the bare wire approach whenever practical and advised a very snug "gas tight" connection. The other preferred well fitting banana plugs or spades with a lot of contact area so as to maximize contact surface. You pays your money and takes your choice.
You're not getting a gas tight connection w/binding post and bare wire.
The biggest issue with bare wire is mechanical degradation and corrosion of the wire. Wire can't be bent infinite times and it will corrode, so you 'll need to periodically remove the wire and clean it, which will involve bending it. After so many bend cycles it'll need to be cut off and re-stripped. Not many people will actually do this. If the cable is multi-stranded it can be a larger PITA to re-strip it. Connectors are simply easier to use, require less maintenance, make better contact w/ the post.
The only downsides to using connectors are cost. This is where spades are clearly better, you can get gold plated pure copper spades for just a few bucks via DH Labs. They are thin and won't last forever, but spending more would get you Furutech spades, which are very thick and have much better quality plating as well, and with rhodium plating it's much harder and more durable vs gold. Similar quality bananas cost more.