On my Linux Mint 19.1:
```bash
$ umask
0022
```

After the first run of `bitcoin-qt -sysperm=false` the `0700` permissions are expected for both the datadir (`~/.bitcoin`) and the walletdir (`~/.bitcoin/wallets`).

Actually, the directories are created with such access permissions:
```bash
$ stat ~/.bitcoin | grep Uid
Access: (0755/drwxr-xr-x)  Uid: ( 1000/ hebasto)   Gid: ( 1000/ hebasto)
$ stat ~/.bitcoin/wallets | grep Uid
Access: (0755/drwxr-xr-x)  Uid: ( 1000/ hebasto)   Gid: ( 1000/ hebasto)
```

Refs:
- #4286
- #13371
- #13389

NOTE: reading through the initial PR #4286 makes me think it was controversial. Is it a better and simpler way to just get rid of `-sysperm` option? I believe a user who needs this option can easily run `chown` command.
return false;
        }
    }
    for (const auto& filter_type : g_enabled_filter_types) {
        InitBlockFilterIndex([&]{ return interfaces::MakeChain(node); }, filter_type, cache_sizes.filter_index, false, fReindex);
        if (!GetBlockFilterIndex(filter_type)->Start()) {
            return false;
        }
    }
    if (args.GetBoolArg("-coinstatsindex", DEFAULT_COINSTATSINDEX)) {
        g_coin_stats_index = std::make_unique<CoinStatsIndex>(interfaces::MakeChain(node), *cachse, fReindex);
        if (!g_coin_stats_index->Start()) {
            return false;
        }
    }
     ********************************************************* Step 9: load wallet
    for (const auto& client : node.chain_clients) {
        if (!client->load()) {
            return false;
        }
    }
     ***
     if pruning, perform the initial blockstore prune
     after any wallet rescanning has taken place.
    if (chainman.m_blockman.IsPruneMode()) {
        if (!fReindex) {
            LOCK(cs_main);
            for (Chainstate* chainstate : chainman.GetAll()) {
                uiInterface.InitMessage(_("Pruning blockstore…").translated);
                chainstate->PruneAndFlush();