What headphones do you have? For open-backs, maybe.

The Sennheiser HD800 came out in 2009 and are still near TOTL. The Stax SR007 were already out since 1998 and are arguably better. The SR009 came out in 2011 and I think are going to be slightly better with EQ. (The bass responds better to EQ. I haven't tested it myself, though.) The HiFiMan Susvara (released about 5 years ago, in 2017) are also arguably better. The Sennheiser HE-1 has been out since about 2016?

We could still get better-tuned Stax in the future (top-tier resolution with top-tier tuning, instead of near-top-tier resolution with top-tier tuning like with the HE-1). There's still slight room for improvement even by current standards.

Closed-back headphones have very much still been getting better, with the Focal Stellia and ZMF Verite Closed released in 2019.