I imagine the reason is that bundling things for free is a lot easier to argue and prove in court. Promoting "first-party offers" is a lot harder.
Note that in most jurisdictions promoting first party offers and bundling is not illegal, what is illegal is to use your monopoly in an area to push competitors out of another. Bundling free things with Office is a pretty clear example of this. Office has essentially a monopoly in enterprise office text documents, presentation software and spreadsheets
Promoting Edge in Windows is not such a clear case, Windows doesn't have a monopoly anymore if you account for phones and macos
iOS App Store shennenigans can always be argued that Apple doesn't have a monopoly in smartphones and smartphones application stores
I know all of this example should sound "obvious abusive behaviour" but you have to remember these things need to be proven in a court of law and if the defendant, even if 100% in the wrong, can drag out a case they will. Therefor it is not worth for the bureaucrats to chase them, it is easier to petition the legislators for more broad laws to make persecution easier first
Note that in most jurisdictions promoting first party offers and bundling is not illegal, what is illegal is to use your monopoly in an area to push competitors out of another. Bundling free things with Office is a pretty clear example of this. Office has essentially a monopoly in enterprise office text documents, presentation software and spreadsheets
Promoting Edge in Windows is not such a clear case, Windows doesn't have a monopoly anymore if you account for phones and macos
iOS App Store shennenigans can always be argued that Apple doesn't have a monopoly in smartphones and smartphones application stores
I know all of this example should sound "obvious abusive behaviour" but you have to remember these things need to be proven in a court of law and if the defendant, even if 100% in the wrong, can drag out a case they will. Therefor it is not worth for the bureaucrats to chase them, it is easier to petition the legislators for more broad laws to make persecution easier first