Apple doesn't support eGPU ... unveiled at CES 2025 (via TechPowerUp), brings Thunderbolt 5 to the range of external GPU enclosures. This increases data throughput to 120Gbps, a marked improvement ...
That's basically what the most powerful GPU you can get in the current 16-inch MacBook Pro (2019) provides – the one you have to spend hundreds more on in a special custom configuration.