You're right that Bitcoin Cash was created to "improve" Bitcoin with a block size increase. Bitcoin Gold, however, was not created in response to a scalability concern.
It was created to provide a more decentralized alternative. Go to your favorite computer retail store chain, or your corner store - can you buy an ASIC and start mining BTC or BCH? Probably not. OK, can you buy a GPU to mine BTG? Yup.
Better yet... do you know anyone who already has a graphics card - maybe a video designer, probably a gamer? Well, they need to spend $0 to buy equipment for mining BTG. They can just install software, join a pool, and start mining. That's how you lower the barriers to entry. That's decentralization.
BTG isn't competing with Bitcoin or other alts - BTG is building something useful and accessible to developers and people, and the ecosystem is improving steadily. In the future, different kinds of coins and miners can co-exist and interoperate more than ever before, and the questions will be: what are people mining? Buying? Holding? Transacting? BTG is steadily building towards allowing more people to do all of those, while making sure it's accessible to everyone - not just the rich and connected.
It was created to provide a more decentralized alternative. Go to your favorite computer retail store chain, or your corner store - can you buy an ASIC and start mining BTC or BCH? Probably not. OK, can you buy a GPU to mine BTG? Yup.
Better yet... do you know anyone who already has a graphics card - maybe a video designer, probably a gamer? Well, they need to spend $0 to buy equipment for mining BTG. They can just install software, join a pool, and start mining. That's how you lower the barriers to entry. That's decentralization.
BTG isn't competing with Bitcoin or other alts - BTG is building something useful and accessible to developers and people, and the ecosystem is improving steadily. In the future, different kinds of coins and miners can co-exist and interoperate more than ever before, and the questions will be: what are people mining? Buying? Holding? Transacting? BTG is steadily building towards allowing more people to do all of those, while making sure it's accessible to everyone - not just the rich and connected.
Upon checking Bitcoin Gold's site, I've found out that the team has updated the roadmap for the project. One of the upcoming features that has brought to my attention is the adoption of Decentralized Mining Pools. If successfully implemented, it could make mining great again as it would allow any average person to mine coins at home. Considering how BTG has been specifically designed to fight ASICs, I'd say that it has a good vision for the future.
Nowadays, Bitcoin Gold is ASIC-resistant because of its unique version of Equihash PoW algorithm. If by any chance, ASIC manufacturers manage to design ASICs for said algorithm, then the BTG team could continue improving the PoW algorithm on a regular basis (the same way Monero is doing). While Bitcoin Gold is not as popular as Bitcoin or Bitcoin Cash, it has potential to become something big in the future if people adopt it massively.
The key here is to bring usability, interoperability, and user-friendliness in order to help attract people into your own cryptocurrency project. This applies to Bitcoin Gold and any other cryptocurrency we know and love today. If BTG lacks this, then it would be nothing more than just a mere cryptocurrency with no future. Things aside, you're right about the Lightning Network. With the atomic swaps, I believe that altcoins would remain alive as they become inter-operable with the Bitcoin blockchain.
Nonetheless, Bitcoin Gold's prices are a bargain these days. Whenever it's right to invest in it or not, it's up to you to determine by researching all about it. Just my thoughts
