I think you're just seeing the "make it work" stage of the combo "first make it work, then make it fast".
Time to market is critical, as you can attest by the fact you framed the situation as "on par with GPT-4o and Claude Opus". You're seeing huge investments because being the first to get a working model stands to benefit greatly. You can only assess models that exist, and for that you need to train them at a huge computational cost.