I recall my son telling me that his expensive bike was stolen from his block of flats when the thief turned up with a battery powered angle grinder to access the pretty solid security cage and then remove the heavy duty lock with which the bike was tethered. My point is, no security cage is impenetrable.
Motion activated security cameras will make everyone’s storage more secure. But your strata committee may feel that isn’t warranted by the level of threat. Home and contents insurance will mitigate against loss if the SC is proved wrong.
Check and see how many thefts and break-ins there have been in the past. You may be installing security that you don’t need.