Grid is not supported by all browsers. Use it if you're sure that you don't want to support old browsers. We rewrote an app from Grid to Flexbox

Imma gonna say bootstrap. Because it is compatible with older browsers. Its okay to learn new technologies, but i think we need to use something that has a wide range of browsers. Also you can think of a fluid layout and use classes from bootstrap and add custom classes that will help were bootstrap can't

PS: i'm a display:inline-block guy

Also: caniuse.com

When I learnt about this and star5ed using it, took me by surprise. Bootstraps fine for a popup site, otherwise grid is better I prefer as you can then customise it where as bootral it's harder

CSS Grid removes the need for things like Bootstrap as it supports fluid layouts.

Having said that I'm still using Bootstrap as I know it very well also I use an abundance of third-party plugins for my web apps that without bootstrap I'd have to find alternatives for.

Bootstrap offers far more then just a layout grid if you're only after the grid then go with CSS Grid.

Check Out this: hackernoon.com/how-css-grid-beats-bootstrap-85d58…

Personally, I'll use the CSS grid or Flexbox over bootstrap. No Container, No extra div's makes HTML code clear to read and No 12 column layout limit which is in bootstrap.