then I read that the 74HC series cannot be used reliably at this link
No, there are probably 1000-billion 74HC chips being used in the field. This is what your
link actually says,
Note that 74HC inputs cannot be reliably driven by 74LS outputs because the voltage ranges used for logic 0 are not quite compatible,
74LS devices are very old style bipolar [NPN,PNP] chips and work at TTL-levels, while 74HC
chips are CMOS and work at CMOS levels, which is basically all you find anymore.
For background, research what TTL and CMOS voltage levels mean.