If i make my main xbox profile home , does it mean i can play games from other profiles?

If you make the console the Home for your main profile, any other profiles that sign into that console will be able to access your main profile's games. They do not have to set the console as their Home.

it is not gamesharing, it is making your main home xbox the home xbox so you and other can play on different profiles and so you cna play offline.

the home setting is not for sharing with others outside of your household, basically be like the rest of us and buy the games or get your friend ti buy the games.

if you cannot afford gaming then that means you have other priorities in life.

Make 1 of the Xboxes the "Home Xbox". When done make sure privacy and sharing preferences are set on the "Home Xbox" to share. After that all the games on the "Home Xbox" are accessible by any profile added to that "Home Xbox. The other (non "Home Xbox) has to have the game purchased under that 2nd Xboxes main profile or purchased as a gift from any profile and sent to a chosen profile to be downloaded when that profile signs onto their Xbox. I have an Xbox One X in my living room controlled by my 2nd account profile. I have a Series X in my game room "Home Xbox" controlled by my 1st profile. Example; I log on the Series X with that main profile and buy/download Division 2 with all expansions and passes. I then log on the One X with my 2nd profile (main for that One X) and buy/download Division 2 with out the expansion and passes. So now a family member adds their profile to the One X, if they own the Division 2 they can play it and as much of the content that I have purchased. To play the full version on the One X someone has to buy it for that console, However anyone else that logs onto the One X with their profile that doesn't own any of Division 2 content can't play it at all. They can launch it but it will direct them to the store. Now adding Ultimate Game Pass to the One X allows profiles to download and play any games available through game pass. Remember my Series X will allow any profile added and signed onto can play any games and use the Ultimate Game Pass to download and play from my Series X. One X has limitations for profiles due to that profile owners games owned and which games are in the One X. Confusing ........ ?

One additional question - if I setup the new Xbox to have the secondary profile from the old Xbox as its main profile, and then take a 2nd Xbox Live subscription on it - does this then mean I effectively have 2 “Home” Xboxes?

Is there a difference in who owns each of these games?

For the purposes of this example, you're Profile A and your brother/family member is Profile B. Console A is the console that Profile A primarily plays on; Console B belongs to Profile B.

So does Profile A own GTA (which is the one that works) and Profile B owns Destiny? (Or maybe the other way around?)

For two users in the same household sharing games, Profile A would need to make Console B his Home Xbox and Profile B would need to make Console A his Home Xbox. My suspicion is that different profiles own the different games and only one of you (whoever
owns GTA) made the other console their Home Xbox, hence the error.

If this is the case, the owner of Destiny needs to make the other console their Home Xbox and then this should work.

Let us know if my guess as to the situation is wrong though, and we can work from there to rectify this.