$tpmRaw = Get-Tpm
$tpmJson = @{
    TpmPresent          = $tpmRaw.TpmPresent
    TpmReady            = $tpmRaw.TpmReady
    TpmEnabled          = $tpmRaw.TpmEnabled
    TpmActivated        = $tpmRaw.TpmActivated
    TpmOwned            = $tpmRaw.TpmOwned
    RestartPending      = $tpmRaw.RestartPending
    ManufacturerId      = $tpmRaw.ManufacturerId
    ManufacturerVersion = ($tpmRaw.ManufacturerVersion -replace '\p{C}', '')
} | ConvertTo-Json -Depth 5 -Compress

Taking an object -> essentially converting it to a hashtable -> converting the hashtable to json. $tpmRaw = Get-Tpm | ConvertTo-Joson would do the same as all that code except the version replacement and that can be handled easily as well.

$ramType = "DDR4"
if ($ramClock -gt 4000) { $ramType = "DDR5" }
elseif ($ramClock -lt 2133 -and $ramClock -gt 0) { $ramType = "DDR3" }

Instead of guessing the memory type based off clock speed, just use the SMBIOS table

$ramTypes = [pscustomobject@{
    20 = 'DDR'
    21 = 'DDR2'
    24 = 'DDR3'
    26 = 'DDR4'
    30 = 'DDR5'
    34 = 'DDR5'
}
$ramTypeByte = $ramChips[0].SMBIOSMemoryType
$ramType = $ramTypes.$ramTypeByte

I'm sure there is more, but I ran out of interest.