Yeah, I guess whichever launcher makes the most sense really depends on which storefront you tend to use most.
I mostly use gog, itch and humble bundle, which lutris handles nicely. On the other hand, it isn't as streamlined as heroic for other stores, you need to install the egs launcher for lutris to run games from that platform, as an example.
Not exactly what you are looking for, but lutris does support itch.io. The way it is implemented, it won't list the bundle contents, but only games that have been added to your collection from the bundles, to avoid cluttering your interface / hide other games you purchased.
If not mistaken, it was included in one of those massive itch bundles a couple years back. If someone is on the fence, you might already have a copy of the game in your backlog ;)
Brushing this off as a data harvesting question seems a bit simplistic in my opinion as it ignores the concern for an EEE strategy.
What happens if they somehow manage to scale up and become the largest instance on the fediverse? Wouldn't they become that de-facto central authority? That would give them the ability to defederate instances which aren't following the "right" code of conduct, effectively silencing them for most of the fediverse users. They could push their own anti-features to the activitypub communication within their apps, forcing the rest of the instances to either follow suit and implement it, or break compatibility with that largest instance (not sure I explain that properly, but an example would be how microsoft and google forced their implementation of the W3C EME specification on Firefox).
Are we supposed to believe that after decades of building walled gardens and prioritising money over ethic, they had a change of heart and decided to embrace open platforms for the greater good of humanity?
One of the most damaging downside could be that this move from Meta is made in the aim to apply some EEE strategy. With that company's history, I doubt there is much to hope in terms of their motivation to join the fediverse.
Also good to note that you could interface with Lemmy through different methods, ranging from apps for your mobile OS of choice, to simplified websites https://join-lemmy.org/apps/
On another note, you can identify some new communities to join through the following page https://browse.feddit.de/