That's simply not true. RISC-V cores, SoCs, and boards perform very comparably to even better than Arm devices with similar µarch e.g. SiFive U74 vs Arm A55, Si

That's simply not true. RISC-V cores, SoCs, and boards perform very comparably to even better than Arm devices with similar µarch e.g. SiFive U74 vs Arm A55, SiFive P550 vs Arm A72, THead C906 vs ARM1176. While Arm CPUs have existed for 40 years, the initial RISC-V spec was frozen and formally published only in mid 2019 and most of the CPUs currently available to buy were designed around that time. This is quite normal. For example the Arm A76 core that features in the latest Raspberry Pi 5 and RK3588 boards (Rock 5, Orange Pi 5) was announced in May 2018, and took until 2022/3 to be available in consumer SBCs. The A53, A55, and A72 had similar time spans from announcement until being available in SBCs: Pi 3 / Odroid C2; Odroid C4; Pi 4. Only in November 2024 was a RISC-V ISA spec suitable for high performance phones, laptops, desktops, servers frozen and published: RVA23. Cores meeting this spec and with expected performance comparable to Arm A78 up to maybe X2 have been announced, but it will be several years before they are available in products. RISC-V is simply very very new. It is doing very well in the markets which it currently addresses.