Is the "anchor" build still viable?
There’s too much for me to even begin. Instead, I’ll just point you in the right direction.
Obal’s PvE guide
https://forum-en.gw2archive.eu/forum/professions/guardian/Guide-DPS-Guardian-for-PVE/first
Harbringer’s WvW guide
https://forum-en.gw2archive.eu/forum/professions/guardian/Guide-World-Vs-World-The-Guardian-and-You/first
And Silven’s PvP guide
https://forum-en.gw2archive.eu/forum/professions/guardian/Silven-s-PvP-Guardian-Build-Guide/first
I believe all three are current and offer not just builds but the theory behind them.
The meta behind each game mode is far too different for there to be a “one build fits all”, unfortunately. But those three threads linked above provide some good insight into the types of builds that would work well for what you’ll need them for.
Yeah you will need to change you traits and gear for each mode.
x/x/30/30/x is a pretty good base for both Spvp and WvW but PVE has a totally different focus.
Anet lied (where’s the Manifesto now?)
There’s too much for me to even begin. Instead, I’ll just point you in the right direction.
Obal’s PvE guide
https://forum-en.gw2archive.eu/forum/professions/guardian/Guide-DPS-Guardian-for-PVE/first
Shanks, the OP specifically asked for not high damage builds and prefers tanky builds. And for that, the anchor build still works great.
However, the reason that everyone on this forum will tell you to run max DPS is because it really is the most efficient way of playing once you gain familiarity with the content, for you and your party. Therefore if you’re not running DPS, expect people to call you selfish and a leecher.
If you don’t want to adopt the DPS meta, my advice is to find friends/guildmates to run content with, or advertise your party with “casual run, all welcome” in the LFG tool. That way everyone’s expectations are met: you get to play how you like, and the DPS meta groups get to play how they like.