@NLS 1.6 is the first version with ActivityPub support, so it's the first version that still is compatible with fully-updated instances

the reason I'm still using it is thus:

partly that my instance is heavily modified and tailored to my own needs, to update would require a ton of effort that i do not have

and partly that i have long since disagreed with the direction Gargron has taken Mastodon anyway; updating would just mean spending time undoing some of the changes anyway