Upgrade from Drupal 6 or 7 when it is right for you
In the era of modern Drupal, release cycles of major versions have only minor importance
TLDR: Drupal 7 has a much longer lifespan than the (already pushed back) official date, and Drupal 8 has an essentially infinite lifespan because it updates in-place to Drupal 9 easily (and the same will be true of Drupal 10, 11, ∞.). There's no reason to rush an upgrade— but there's no reason to wait either.
That's the short version.
A client recently wrote to Agaric about Drupal 7 / Drupal 8 / Drupal 9 project planning questions:
With the EOL for Drupal 7 in Nov of 2022, and the EOL for Drupal 8 in Nov 2021, is there a reason we should move a D7 site to D8 at all this year? Seems like we might want to move directly to D9? We don’t want to feel pushed up against a wall with a “new” site build in Drupal 8, if we can limp along in D7 for a couple more years while we develop a D9 site with a longer lifespan. I’m wondering if you might have time to discuss pros and cons briefly so we can get a good plan together for moving forward.
I started typing and almost did not stop:
No one believes me when i say this, but i repeat my assurance that Drupal 7 will be well-supported commercially until 2030 or later (Drupal 6, released in 2008, still has semi-official long term support until at least February 24th, 2022— and Drupal 7 has a larger install base than Drupal 6 ever did, and currently has the largest install base of any version of Drupal by far, with more than half a million tracked installs.
Drupal 7 will be supported by the community for a long time. You do not have to feel pushed to a new version, like, ever.
We do recommend moving directly to Drupal 9 (which was released on June 3rd of 2020), however:
Moving to Drupal 8 or to Drupal 9 is much the same. Drupal 8 starts what i call the "modern Drupal" era. Whereas for going from Drupal 5 to 6 or 6 to 7 or 7 to 8 broke backward compatibility and might as well be a full rebuild (so we would often recommend hopping a version, say, stay on Drupal 6 and wait for Drupal 8 to be ready) going from Drupal 8 to 9 is closer to going from Drupal 8.8 to 8.9— an in-place upgrade from 8.9 to 9.0. Going from 9 to 10 will work the same, and that's the plan and promise for Drupal 8 on out.
All that said, if anything significant needs fixing on your current Drupal 7 site, or you are looking to make any improvements, you'll want to do that on Drupal 8+ or Drupal 8/9 as we phrased it back when Drupal 9 was still a pretty recent release, but now we can just say Drupal 9— or, as i call it to emphasize the decreased importance of major version numbers, modern Drupal.
Agaric is always happy to discuss more! Mostly what i'm saying here is the useful things to talk about are the specific goals for the sites—when you want to accomplish what—because the official support cycles are a distraction in the current context of Drupal. So make sure your current site is maintained, but take your time to get clear on your objectives, and contact Agaric or the Drupal professionals of your choice when you think it might make sense to upgrade your site into the era of modern Drupal.