tl;dr yes but you would probably get beaten to the punch by high frequency traders, and risk being exploited by the discloser.
If you had sneaky exclusive access to their trading flow in real time then yeah sure you could copy them and get the benefits of insider trading. (And you might be guilty of insider trading yourself? I'm not sure how the law works.)
If everyone knows Alice is doing insider trading and knows her trades, then when Alice buys X at $10.00, there will probably be other copycats piling into X and driving its price up, so you won't be able to get the same price as Alice, unless you're faster than everyone else.
Since you don't know what the actual inside information is, you don't know if it's still worth it to buy at $10.20, $10.30, etc. Maybe the inside info was only slightly better than expected earnings and the price end up being only $10.05.
This is somewhat exploitable by Alice, she doesn't need insider information anymore, she just has to buy random stock Z and disclose it, watch copycats pile into Z and drive its price up, then sell it back at a higher price.
