Well, Dio is likely stronger physically than DIO by some degree, even if not much, and he has confirmed better and quicker regen, plus flash freeze and SRSE, plus DIO can't actually kill Dio, he has nothing to permanently bypass that regen, while Dio does in the form of freeze.
But DIO has one key critical factor, one factor that turns a losing battle into a, pun only slightly intended, steam roll, an invisible punch ghost that Dio can't touch, see, harm, or interact with, that can stop time and can straight up throw hands and kick his ass.
If you tossed Dio and DIO in a room together, Dio would beat DIO, he has better innate physical qualities plus flash freeze can actually gimp DIO due to compromised healing.
But once you add The World? Dio's tough but decisive win becomes Dio getting ******* ragdolled and tossed around by an invincible and invisible force he can't do shit about, that can stop time. Assuming The World doesn't bash Dio's skull in and tears him apart so badly he can't regen properly, or at least not without it taking a long ass time (this wouldn't happen in one or two punches mind you, but nothing is stopping TW from stopping time and just unleashing thousands of blows and ripping him apart, and then doing it again because Dio can't do shit in retaliation against TW, and then again, and then again, and again, and then etc), the best case scenario for Dio is that DIO stalls Dio till day, and then just has The World grab Dio and toss his ass out into the light because Dio ain't defeating DIO when he's protected by something he literally cant see or hurt that can stop time allowing them to dismantle him or dodge his attacks, and he also can't escape given time stop goes brrrrrr, see the scene with the senator.
Plus, DIO knows what Dio can do, but Dio doesn't, plus DIO is more experienced and more genre savvy and is more willing to not **** around due to, coincidentally, his **** up as his time as Dio.
5m is also within TW's manifestation range, which is 10m, though range barely matters as he can just stop time and get in, or even out of range if he has to.
Basically.
Dio>>DIO. A tough but ultimately assured win.
But TW>>Dio. Like a athletic dude but still just a dude trying to roll up to Mike Tyson, but he's a ghost, and he can stop time.
Stando powah da goes brrrrrrr.