> It lacks any modern browser (and probably the power to deal with https)
It should be able to run Netscape 4, but HTTPS will indeed be an issue - less because of speed, more because a browser that old will lack support for modern cipher suites.
Also: gopher://magical.fish has tons of services, among gopher://sdf.org
for phlogs and gopher://bitreich.org/1/lawn for a big directory.
And, by connecting to the public servers of http://bitlbee.org with any IRC client you can access modern IRC+TLS servers and a good chunk of protocols too (Discord, Mastodon, Steam, Jabber, Linc, Facebook chat, Telegram....)
If you mean the updated MacLynx I've been working on, I don't have TLS in it yet, but now that the PowerPC version is back I'm planning to embed Crypto Ancienne in it for opportunistic TLS 1.3 (unfortunately too much for anything less than a high end 68040).
It should be able to run Netscape 4, but HTTPS will indeed be an issue - less because of speed, more because a browser that old will lack support for modern cipher suites.