in a stock exchange where fractional share purchasing is allowed, what is the point of a stock split.???

i am a stock market beginner,

I came across the google 20:1 stock split news, and apart from increasing its share trade volume for a while, how does this affect/impact a stock in a market where fractional shares are allowed to be traded?

if it was a market where u can only buy whole units like 1, 2 shares, it is different and many people will enter the market seeing the low price.

if there is no change in the stock returns lets, say the average of google to be 10 %, and even after the split the returns is 10 % ( which is unlikely coz people would start to buy the stock for the split now), what is the point of a split.

i am. asking all this becoz berkshire Hathway never gave a split , and the share price is more than $450,000… now i cant but afford that much money , but surely invest a $500 or 1000 in it through fractional buying ?