Risk is defined by what can be lost. If you bought a $200 video card early on and spent $200 on electricity mining than your risk was $400. Contrarily someone right now buying a single bitcoin is going to be risking a lot more than just that.
Early adopters invested almost nothing compared to the amount of money moving around now (at risk on a speculative investment). Their risk was negligible and certainly far less than folks getting into the game now, coin for coin.
You’re right that if one buys 0.05 btc today for $400, it’s the same risk as someone investing $400 years ago to mine hundreds or even thousands of coins, but real investors aren’t buying 0.05 btc.