Hmm...challenging the error margin of a specific calculation result of a specific model based on confirmed inconsistencies is regarded as "opinion-based". Interesting. Just curious, is the rationale of closing a "opinion-based" question also "opinion-based"?
According to the calculation of the cosmological standard model $\Lambda CDM$, the age of the Universe is 13.8B years old. This claim is more or less supported by observation of oldest galaxies/stars in the universe.
But is 13.8B really accurate as inferred by $\Lambda CDM$?
Recently there were alarming inconsistencies turning up regarding the Universe's late-time history at low redshift, evidenced by the contradicting numbers of Hubble constant ($H_0$) measured by supernovae/cepheid variable ladders with what is predicted by $\Lambda CDM$ which is calibrated from CMB (Cosmic microwave background) observations and BAO (Baryon acoustic oscillations) constraints. This contradiction is called Hubble tension, or even "Hubble crisis" according to some cosmologists.
If the Hubble tension turns out not to be a systematic measurement error, it could have real implications on the accuracy of dark energy density ($\Omega_\Lambda$) and the true age of the Universe. The standard cosmology model $\Lambda CDM$ has been known as the "concordance model". Given the "Hubble tension" and other inconsistencies (e.g. the controversy surrounding $\sigma_8$), are we sure $\Lambda CDM$ is a "concordance model"?
Shall we take $\Lambda CDM$'s calculation of the Universe being 13.8B years young with a grain of salt? Should we put a much higher error margin on the claimed age number? In other words, I am questioning that when the Hubble tension is eventually resolved, a new value for the age might exceed the bounds of the commonly agreed +/- uncrtainty error that accompanies the 13.8B value.
Added note: see a related question here.