The hibernate feature no longer available?

Hibernate will be deactivated if your using any Virtualization Tech, like 'Defender Application Guard' or 'Hyper-V'.

As KapilArya has suggested, there are many reports to assist in diagnosing sleep states in powercfg

powercfg /AVAILABLESLEEPSTATES
The following sleep states are available on this system:
    Standby (S0 Low Power Idle) Network Connected
    Hibernate

The following sleep states are not available on this system:
    Standby (S1)
        The system firmware does not support this standby state.
        This standby state is disabled when S0 low power idle is supported.
        The current power policy has disabled this standby state.

    Standby (S2)
        The system firmware does not support this standby state.
        This standby state is disabled when S0 low power idle is supported.
        The current power policy has disabled this standby state.

    Standby (S3)
        The system firmware does not support this standby state.
        This standby state is disabled when S0 low power idle is supported.
        The current power policy has disabled this standby state.

    Hybrid Sleep
        Standby (S3) is not available.
        The hypervisor does not support this standby state.

    Fast Startup
        This action is disabled in the current system policy.

it will not become available if you have some virtual machine technologies installed and running in your windows, like defender application guard or sandbox etc.

.... annoying i know

Not true, I use hibernate on my laptop all the time and it has 32GB of ram, idk how it works but it boots faster than normal cold boot up. 

Can you share us which build you're currently on?

Have you tried enabling hibernation using powercfg /hibernate on command?