Sadly, without an accompanying FPGA-implementation of an FPU it's much less useful for productivity work/research, i.e. outside of 08/15 gaming and application fare. Same with Ao486, which only implements a 486SX.
First, FPUs are complex and FPGA support for floating point is limited. There's DSP blocks for integer additions and multiplications. But very little FP support.
Second, the CPU itself may not be fast enough for an FPU to matter much. Quake wants at least a 75 MHz Pentium, while ao486-MiSTer is closer to a 486-66. So we probably need both a faster CPU design and a faster FPGA. Maybe Altera's new Agilex 5 will be useful here.
Can you name some? I cant come up with any real world uses of FPU implemented PC for industrial use. Even MISTER is pushing it considering availability of emulation.
So much for needed. Packages that run without, but are only fully useful with an FPU, were relatively common.