What would the world look like if borrowing money didn’t exist?

I'd agree we would have less development, perhaps more value for money (i.e. less inflation). Islamic Banking as Jimmy Wales as cited, keeps money in circulation, i.e. you're discouraged from hoarding money. Money is either invested or transacted into the economy to keep it flowing. Think of money in Islamic banking as water. Stagnant waters are not preferred.

Because borrowing essentially had the multiplier effect on the economy, access to capital led to faster development of rural areas and brining under or undeveloped regions at par with developed regions.

Growth would definitely be slow. That's for sure.