Comparison of the retrieved atmospheric metallicity of V1298 Tau b and c with those of mature exoplanets, with Solar System planets, and with young directly imaged planets orbiting HR 8799 (30 Myr old). The left panel shows these planets in the metallicity-orbital distance plane and the right panel shows the mass-metallicity distribution of these planets. The atmospheric metallicities of the two V1298 Tau b and c planets were derived from the ATMO retrievals (Table 2). The stars show metallicities for retrievals performed using 10 M_⊕ for both planets and the squares for retrievals using 23 and 50 M_⊕ for planet b and c, respectively. The metallicities of the HR 8799 system (blue circles) were obtained from Nasedkin et al. (2024). The gray points show metallicity constraints from pre-JWST observations (mostly driven by HST) taken from Wakeford & Dalba (2020) and the magenta points show metallicities derived from JWST observations (table uploaded to Zenodo). For planets that both appear in the sample of Wakeford & Dalba (2020) and have been observed with JWST, we plot the latter. For planets where metallicity was estimated from grids, we do not plot error bars. A comparison between the measured metallicities of the V1298 Tau and HR 8799 systems shows that these planets have very different atmospheric metal enrichment, indicative of differences in their formation mechanism, disk properties, and location. The dashed red line in the right panel shows a mass-metallicity relation derived in Thorngren & Fortney (2019). The V1298 Tau planets have metal-poor atmospheres by an order of magnitude compared to their mature counterparts and the observed mass-metallicity trend among exoplanets.