You pretty much have to, yeah. Each platform has its own optimizations for its type of content, like Loops specializes in videos and the Threadiverse in link aggregation or text and pics.

That said, you can check out Mbin to at least lessen the number of accounts somewhat: it looks to me too focused on the needs of microblogging (e.g. longer titles that even span multiple lines), and last I checked had an enormous amount of wasted space for more Threadiverse style content (with tiny titles, perhaps a single word even). Although even noticing that could make you feel better about creating a new account for each service:-). It just goes with the territory.

Likewise, PieFed allows integration with Friendica and is expanding upon tighter integration with Mastodon... but it is primarily optimized for integration with Lemmy-style content more than anything else.