Is it? I would guess that people already split their traffic between a home workstation connected through a local ISP, a mobile phone connected through a national carrier ISP, and a work computer that is connected with a (third) enterprise ISP. The concerns that linger in the comments here, are about the dangers of exposing even a slice of your metadata can be disastrous.

Therefore, going from three to eight ISPs is arguably worse as your exposed to nearly 3x the risk of exposure.

The more information any one entity has about any individual, the more accurate a profile they can create. The more thinly spread your metadata is, the harder it is for any one corporation to create a profile. Clearly there is no perfect solution, it depends on what sort of privacy risks you are trying to mitigate.