Identifying Titanic Victims Today

I saw a list of still unidentified bodies from the RMS Titanic recently and I was surprised that so many bodies with a lot of information still remain unidentified. Some examples of them are posted next

NO. 28. - MALE. - ESTIMATED AGE, 30. DARK - HAIR & COMPLEXION.

CLOTHING - Black coat; grey trousers; check shirt; black boots.

EFFECTS - Nothing found but table ticket and address. "Shakin Bros., 155 Broad St., Ottawa.

PROBABLY THIRD CLASS. ITALIAN.

NO. 36. - MALE. - ESTIMATED AGE, 35. - HAIR, DARK.

CLOTHING - Steward's uniform.

TATTOO MARKS - Left arm, all over; right forearm, clasped hands and heart, Japanese fans on breast.

EFFECTS - Gold ring on right little finger, engraved "Madge"; gold watch and chain; seal; silver match box; keys; wine cards; etc.; gold and brilliant brooch; 6 pence.

CREW; 1st CLASS STEWARD. No. 76

NO. 44. - MALE. - ESTIMATED AGE, 21. - HAIR, LIGHT.

CLOTHING - Stewards coat with blue pants' white shirt, marked " F. W. I."

EFFECTS - Only things found were keys marked "C deck linen locker."

STEWARD.

NO. 78. - MALE. - ESTIMATED AGE, 40. - HAIR DARK; MOUSTACHE LIGHT.

CLOTHING - Dungaree coat and trousers; flannel singlet; no boots or socks.

TATTOO - On left arm; 'E. G.' anchor, clasped hands and heart; sailor; right arm; anchor and woman.

NO EFFECTS.

FIREMAN, PROBABLY ON WATCH.

These ones look very easy to identify and by quick inspection of the rest of the bodies, a lot of them seem to have tatoos on their arms, would a relative not have come forward to say that the person they lost had a tattoo? I know for example that at this stage, especially the ones buried at sea, it would be nearly impossible to identify bodies from descriptions such as these:

NO. 48. - MALE. - ESTIMATED AGE, 35. - HAIR AND MOUSTACHE, LIGHT.

CLOTHING - Steward's coat, vest and trousers; flannel shirt.

NO EFFECTS. MARKS, OR PAPERS FOUND.

STEWARD.

I was under the impression that there are plenty of Titanic Researchers, but after 100 years how much more can they investigate before coming back to these bodies?