Eventually, itll be too big for your opponents to ignore, and will eat a Go for the Throat, but if it gets to six +1/+1 counters before that happens, youve paid two mana for three cards, six life, and 12 extra damage
Over the years, it has become fair easier to get monsters into the GY, as Link monsters allow players to use numerous material to make powerful boss monsters and set up the GY easily
Being more challenging to cast sounds like a downside, but Ive always maintained that it doesnt really matter for spells with higher mana values
Also, it's not used nearly as much anymore simply because cards that could remove things in the Spell/Trap zone at the end of your turn, if you go second, are more prevalent nowadays (Cosmic Cyclone, Twin Twisters, Mystical Space Typhoon, etc)