Exactly.. the congestion has forced people to go to other altcoins like Ethereum and Ripple..
It's not a coincidence that around February 2017 when the average blocksize started getting closer to its 1 MB limit the Bitcoin dominance sharply fell from 86% to an all-time low of around 39%. The price was still rising but the rest of the money went to the other altcoins.

If Bitcoin still retained even just 80% of our current marketcap of $152B (Aug.23,2017) Bitcoin's price today could have been $7323.87 per Bitcoin

https://coinmarketcap.com/charts/#dominance-percentage

https://blockchain.info/charts/avg-block-size?timespan=2years

As of this writing only 116 Blocks remain to be mined before Segwit activates, which means it will activate tomorrow (Aug. 24)
https://xbt.eu/

Segwit will give a temporary solution of increasing the capacity but keeping the 1 MB limit by separating the Transactions from the Digital Signatures, proof or witnesses that the transactions are real (i.e. Segregated Witness)

Meanwhile, Bitcoin Cash ALREADY has the capacity to accept around 8x the amount of transactions the legacy chain can handle right now.